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Full text of "Programme of studies for the high school"

OOBBPLIIi 



LB 


1629.5 


A3 


A35 


1946 


gr. 10-12 


bull. 5b 


CURR»HT 



0x mm 

ummKfmu 




Price 20c 



Education 




m^i 



[ALBER J-AJ 



Prosramme of Studies 
For The High School 



BULLETIN 5b 



Guide for Practical and 
Experimental Work 

... IN ... 

PHYSICS 2 
CHEMISTRY 2 
BIOLOGY 2 



Additional copies of this Bulletin may be had from the 

General Office of the Department of Education at 20 cents 

per copy. 



EDMONTON: Printed by A. Shnitka, King's Printer. 
1946 



o 



FOREWORD 



"Laboratory work" in any one of the senior science courses 
is NOT a course in itself, separate and distinct from a course in 
theory. It is not designed to produce research students, but 
rather to illuminate the facts and theory of the subject, and pro- 
vide, along with other activities, some meaningful experience for 
the student that may facilitate his comprehension. Teaching and 
practical work must therefore go hand in hand, and be kept in 
step. Failure to synchronize theory and practical work defeats 
the purpose of a course in science. Students who memorize the 
theory without having had the benefit of practical exercises can- 
not meet the requirements of any science course ; but, on the other 
hand, there can be little justification for a procedure that permits 
the practical work to outrun the theory, or that concentrates the 
practical work in a few weeks at the end of the term. 

The outlines for practical work in chemistry, physics and 
biology given in this Tbulletin are suggestive rather than prescrip- 
tive. More exercises may be required to meet the needs of a par- 
ticular class; and other and better exercises may be devised by 
the teacher in consultation with his students. The suggested out- 
lines will, however, save some of the teachers' and students' time. 

This bulletin is to be used as a guide to practical and experi- 
mental work and not as a student workbook. That is, students 
should not write answers to questions, give observations or tabu- 
late results in this book but should be required to make all nota- 
tions in a suitable notebook. 

It is recommended that, wherever possible, experiments be 
performed by groups of two and that each student be required to 
keep a record of the experiments carried out. Written reports on 
selected experiments should be done in an approved manner, us- 
ing carefully-labelled diagrams, equations or statements of basic 
scientific principles when any or all of these will add to the quality 
of the report. These written reports should be kept in a separate 
notebook, looseleaf preferred. 



:>ROVi:^ClAL ARCHIVES 
OF ALBERTA 




UNIYERSIIT LIBRARY 
UNIVERSITY OF ALBERTA 



THE SCIENCE LABORATORY 

Some of the statements made in the introductory section of 
Bulletin 5a may be appropriately repeated here. It was men- 
tioned, for example, that some schools do not have the use of an 
extra room for a science laboratory; hence all practical and ex- 
perimental work has to be done in the regular classroom. In such 
cases, the comments made concerning the science room should be 
carefully noted. 

Where a separate room for laboratory work is available, it is 
best that it be conveniently located in the school building, well 
lighted and ventilated, supplied with good apparatus, adequately 
furnished and given proper care. 



ATTENTION TO ENGLISH 

The suggestions found in Bulletin 5a under the heading, "The 
Importance and place of English in the Science Courses", are 
also appropriate for this bulletin. In the section referred to, it 
was stated that students of science should be able to participate 
successfully in certain science activities that are common in their 
school and everyday lives. The activities named are: 

1. Reading, 

2. Taking part in discussions, 

3. Preparing and making reports, 

4. Giving descriptions and explanations. 

All these activities are present in a well-balanced science 
course. In laboratory work particular attention should be given 
to activities 3 and 4. In these activities, several particular 
abilities will have to receive special attention, such as mastery 
of vocabulary, spelling, punctuation and effective expression. 
Where basic principles are involved, they should be stated 
accurately and, in written reports, placed in a prominent position. 
In all cases, the instructor is at liberty to devise methods of 
procedure for his students that will meet desired objectives and 
requirements of the respective courses. 



PHYSICS 2 



The experimental work in Physics 2 will consist partly of ex- 
periments demonstrated by the teacher and partly of experiments 
designed for individual work or for groups of two or three stu- 
dents working together. 

The twenty experiments in this outline have been selected for 
individual work on the basis that each requires some quantitative 
observations and involves some definite calculations leading to a 
specific result. Completed experiments, with a reasonable degree 
of accuracy, should be expected of all students. 

The experiments are in two groups, the first ten dealing with 
Mechanics and Heat, the second ten dealing with Magnetism and 
Electricity. A minimum of seven in each group should be done 
by each student. 

Owing to the fact that much of the apparatus for these ex- 
periments is expensive, it is suggested that only one or two sets 
of apparatus for each experiment should be provided. This will 
make it necessary for groups to perform the experiments in 
rotation. 

The list of apparatus provided below is based on the assump- 
tion that many of the experiments will be running concurrently 
where larger classes are involved ; hence the necessity for several 
of such instruments as ammeters and voltmeters. An adequate 
supply of such equipment should be built up in each school over a 
period of years. This list does not include demonstration equip- 
ment. There is practically no limit to the amount of equipment 
a teacher will find useful in teaching this course. It can be added 
to indefinitely, but much of it may be improvised or constructed 
by students at home or in the school shop. 



List of Apparatus for Physics 2 

3 spring balances (250 gm.) 

3 spring balances (2000 gm.) 
*1 spring balance (15 kgm.) 
*1 parallelogram of forces board 

11" perforated metal ball 

3 large retort stands and clamps (iron) 

1 wooden stand and clamp 

1 board for friction experiments 

1 set of kilogram weights on hook 

1 set of gram weights on hook 

1 wheel and axle 

1 metre stick 

1 inclined plane and car 



3 insulated calorimeters 

6 thermometers (centigrade) 

2 thermometers (Fahrenheit) 

3 physical balances 

3 sets of metric weights 

1 aluminum block for specific heat experiment 
*1 Liebig's condenser 

*1 distilling flask 

*1 boiler for heat experiments 

2 water traps 

1 Regnault's dewpoint hygrometer 

1 Wet and dry bulb hygrometer 

6 bar magnets (6" long) 

1 horseshoe magnet 

1 box of fine iron filings 

1 roll of blue print paper 

1 grooved board for bar magnets 

1 demonstration Voltaic cell 
6 zinc elements for the above 

4 copper elements for the above 

2 carhon elements for the above 

3 Daniell cells 
3 dry cells 

3 voltmeters (low range, D.C. graduated in tenths) 

3 ammeters (low range, D.C. graduated in tenths) 
*1 voltmeter (A.C. 0-150 volts) 
*1 ammeter (A.C. 0-10 amps.) 

1 resistance box (plug-in type) 

1 resistance box (dial type) 

1 set of assorted standard resistances 

1 variable resistance (0-3 ohms) 

1 storage battery (6 volts) 

6 knife switches (s.p.s.t.) 

1 Wheatstone bridge (slide wire type) 

1 D'Arsonval type galvanometer 
12 pietenpol connectors 

6 test clips 

1 mercury barometer 

1 galvanoscope (multiple coil type) 

6 small compass needles (enclosed) 

1 demonstration compass needle (open) 
*1 St. Louis type demonstration electric motor 
*3 40-watt lamps (Mazda) 
*1 25-watt lamp (Mazda) 
*1 60-watt lamp (Mazda) 
*1 100- watt lamp (Mazda) 
*1 16-c.p. carbon lamp 
*1 32-c.p. carbon lamp 

1 set primary and secondary coils with core. 



In addition to the above, assorted beakers, flasks, test tubes, 
measuring cylinders, glass tubing, rubber tubing, rubber corks, 
tripods, bunsen burners or spirit lamps, reagent bottles, battery 
jars, porous cups, wire gauze and other chemical equipment will 
be needed. 

Special chemicals for these experiments include : 

Sulphuric acid 

Nitric acid 

Hydrochloric acid 

Mercury 

Copper sulfate 

Sodium dichromate 

Ether 

Ethyl alcohol (95%) 

Methyl alcohol 

*The apparatus marked with an asterisk is less essential or 
expensive equipment which is required for only one experiment 
and could be omitted. 

EXPERIMENT 1 
The Parallelogram of Forces 

Object: To demonstrate the proposition known as the paral- 
lelogram of forces, and to calculate the equilibriant of two forces 
acting at any angle. 

Reference: ''Modern Physics," Sections 131-136. Study the 
definitions of ''Resultant of two Forces acting at any angle," and 
"Equilibriant of two or more forces." 

Apparatus: Three spring balances graduated in grams, a 
small iron ring (diameter 1")> string, drawing paper, thumb 
tacks, either three 3" nails or perforated board and pins as listed 
in science catalogues. 

Procedure: If the prepared board is available, tie three 
lengths of string to the iron ring, place the three pins in holes at 
the extreme ends of the board and adjust the three spring bal- 
ances on the board so that when the three strings are tied to their 
hooks and their rings are placed over the pins they will each 
reigister a tension at about the middle of their scales. 

If the board is not available, use the three 3" nails driven 
firmly into an old table or bench so that they form a triangle with 
sides about three feet long. The spring balances are attached to 
these nails and to the iron ring by means of lengths of string, 
with the iron ring approximately in the centre of the triangle. 
Place a sheet of drawing paper under the strings with the iron 
ring in the centre and attach to the board or table by means of 



tacks. Make sure that the balances are stretched with as little 
friction as possible against the board or pins. Using a set square, 
mark two points vertically below each string, one at each end, so 
that when these points are joined with straight lines they will 
exactly represent the direction of each string. 

Now read each spring balance as accurately as possible and 
record its value in grams on the paper along the string attached 
to it. Remove the balances from the pins, join up the points on 
the paper so that they meet in a point. 

Along two of the lines mark off lengths proportional to the 
readings of the spring balances. A suitable scale might be 1 cm. 
to represent 20 gm. Taking these two lengths as the two ad- 
jacent sides of a parallelogram, complete the parallelogram using 
a compass to mark off equal opposite sides. 

Draw the diagonal of the parallelogram, measure its length 
in centimetres and express it as a force in grams on the same 
scale as you used for the sides of the parallelogram. 

Results: Is the diagonal of your parallelogram in the same 
straight line as the line representing the pull of the third balance? 
If your work was done accurately and the balances registered cor- 
rectly with the minimum of friction, this should be the case. 

Does the length of the diagonal in centimeters represent the 
same value in grams as the third balance? 

Letter your diagram ABCD etc., and state in the lower right- 
hand corner of the paper which lines represent which forces, 
which is the resultant force and which is the equilibriant. Write 
a statement in ink of the proposition which you have thus 
demonstrated. 



EXPERIMENT 2 

The Simple Pendulum 

Object: To study the laws governing the oscillation of a pen- 
dulum and to find the value of g, the acceleration due to gravity. 

Reference: ^'Modern Physics,'* Sections 162-166. Study the 
definitions of ''single vibration," ''complete vibration," "period," 
"amplitude of vibration." 

Apparatus: About 4 feet of strong thread, one inch metal ball 
perforated through the centre, or other suitable pendulum bob, 
clamp, stop watch or metronome. An ordinary watch with a sec- 
onds hand may be used if a stop watch or metronome is not 
available. 

Procedure: (a) Tie the thread to the metal ball and secure 
the other end by means of a clamp, adjusting the length of the 
pendulum so that it is exactly one meter from the point of sus- 
pension to the centre of the bob. Pull the bob to one side through 
a small arc, not more than three inches, and release it. When it 
is swinging uniformly, take the time in seconds for it to make 30 



single vibrations. Two students working together can do this 
quite accurately with an ordinary watch if one watches the pen- 
dulum and gives the time for starting and stopping the count, 
whilst the other observes the seconds hand of the watch. 

Repeat the experiment with the pendulum swinging over a 
larger arc, say, six inches, and again with an arc of about one 
foot. Keep a record of your results. 

(b) Shorten the thread so that the effective length of the 
pendulum is 25 cm., and determine the average period of oscilla- 
tion; i.e., the time for one complete vibration of the pendulum. 
Use a small arc and take the average time for twenty complete 
swings, using several tries. Record the results. 

(c) Repeat the experiment using a pendulum with an effec- 
tive length of 64 cm. Record the average value for the period of 
oscillation. 



Results: ' 


Tabulate your results from experiment (a) thus: 


Exp. No. 


Amplitude 
(approx.) 


No. of single 
vibrations 


No. of 
sees. 


Period for 
single vib. 













What is the relation between the time of vibration and the 
amplitude? State the result as a law. (See Section 163 of text- 
book.) 

Tabulate your results from experiments (b) and (c) thus : 



Exp. No. 


Length 


V Length 


Period for 
complete vib. 


Value of g. 


a 
b 
c 











How is the time of vibration related to the length of the 
pendulum? State this as a law. (See Section 163 of textbook.) 
Determine the value of "g'' by using the formula. 



T = 2 



g 



EXPERIMENT 3 

The Coefficient of Friction 

Object: To determine the coefficient of sliding friction and 
to compare it with rolling friction. 



Reference: ''Modern Physics," Sections 183-190. Study Sec- 
tion 187 and the definition of "coefficient of friction." 

Apparatus: A board 5 ft. long and 4 or 5 in. wide, preferably 
of fir or other hard wood, planed and smoothed with sandpaper, 
a small block of the same material about 3'' x 5" x 1", spring 
balance, kilogram weights, small experimental car, string. 

Procedure: (a) Insert a small hook in the centre of one end 
of the wooden block, suspend it from the spring balance and 
record its weight in grams. Lay the long board flat on a bench 
and rub the small wooden block over it several times. Attach a 
string to the hook on the block and tie the other end to the balance 
as in Fig. 221 of the textbook. Pull gently on the balance and 
tap on the board so that the block just starts moving. Read the 
balance at this instant. Repeat several times and determine the 
average force of friction. Record all readings in tabular form. 

Now place a kilogram weight on the wooden block and repeat 
the experiment, again recording the readings of the balance and 
determining the average force of friction. 

(b) Place a stop against one end of the board and lay the 
wooden block on the board. Raise the other end of the board 
until the block begins to slide down the slope. Note the approxi- 
mate angle of repose; i.e., the greatest angle at which the block 
remains in equilibrium on the inclined plane. Place a support 
under the board and adjust the slope of the plane so that when 
gently tapped the block will begin to slide down the slope. Meas- 
ure the vertical height of the slope and the length of the base line 
along the table. For accurate measurement, the slope of the 
triangle must be produced and the exact point at which it meets 
the table marked. The dimensions of the right-angled triangle 
should be carefully recorded and the angle of the plane at the 
base determined with a protractor. 

(c) Lay the board flat and place the trolley car on it. Gently 
raise the board at one end until the car begins to move evenly 
down the slope. Determine the height and base of the triangle 
so obtained as before. 

Now lock the wheels of the car with a wedge and repeat the 
experiment determining the dimensions of the slope down which 
the car slides with locked wheels. 

Results: Determine from the data of experiment (a) the 
coefficient of sliding friction as worked out in Section 187 of the 
textbook. 

Is the value the same when the block carried the kilogram 
weight? 

From the data of experiments (b) and (c) the coefficient 
of friction may be determined by the formula, 

p ^ _ Vertical height 
' "~ Length of base 
How do the results of experiment (a) and (b) compare? 
These two methods should give approximately the same results. 
The coefficient of friction may also be obtained by determin- 



10 

ing the tangent of the angle of friction. That is, if the angle 
between the board and the table at the base is i, the coefficient of 
friction =tan i. The results of this method should again check 
with those obtained above. 

From the data of experiment (c) determine the coefficient 
of rolling friction and the coefficient of sliding friction. Which 
is the greater ? 

Tabulate the results of experiments (a), (b), and (c) in 
three separate tables, setting forth the weights used, the force of 
friction, the dimensions of the slopes and the calculated coeffi- 
cients for each set of values. 

EXPERIMENT 4 

Part A — ^The Wheel and Axle 

Object: To determine the mechanical advantage of the wheel 
and axle. 

Reference: "Modern Physics," Section 214-215. Study the 
method of determining the mechanical advantage of the wheel 
and axle as given in Section 214. 

Apparatus: An experimental wheel and axle may be obtained 
from scientific supply companies, or it may be simply constructed 
by obtaining two wooden spools or cylinders, one large and the 
other small, and gluing them together coaxially- Nails may be 
driven into the centre of each spool to form an axle which can rest 
in two short lengths of glass tubing for bearings. The wheel 
and axle should turn symmetrically on these bearings which may 
be lubricated with oil to reduce friction. A small hole bored 
diagonally through the rim of each cylinder will provide points 
of attachment for strings. A small tray to carry weights may be 
made from the lid of a round can with holes bored around its rim 
for the supporting wires or string. 

Procedure: Set up the wheel and axle and see that it turns 
without wobbling and with as little friction at the bearings as 
possible. Tie a string to the small wheel or axle and pass it 
around the circumference twice. To the other end of the string 
tie a 500 gm. weight. Tie a string to the large wheel and pass 
it around its circumference in the reverse direction to the string 
around the axle. Attach the tray, previously weighed, to the 
other end of this string. Now place weights in the tray until the 
wheel and axle remains in equilibrium with both weights hanging 
freely. Record the weights used and measure the diameters of 
the wheel and axle using a pair of calipers or dividers. Record 
the diameters in centimetres correct to the second decimal place. 

Repeat the experiment using a 200 gm. weight and again 
with a 1000 gm. weight. Record the weights needed to balance 
these in each case. 

Results: Determine the theoretical Mechanical Advantage of 
this system from the dimensions of wheel and axle as explained 
in Section 214 of the textbook. Determine the actual mechanical 
advantage by dividing the weight by the effort for each experi- 



11 

ment. Compare the theoretical mechanical advantage with the 
true mechanical advantage. 

Tabulate results as follows : 



Diam of 
Wheel (cm.) 


Diam. of 
Axle (cm.) 


Theor. 
M.A. 


Weight 
Raised 


Effort 

W+w 


Actual 
M.A. 















Note: In above table W is the weight placed in the tray, w is the 
weight of the tray. 

Part B (optional). 

Reference: "Modern Physics," Section 223. 

Apparatus: Bicycle, kilogram weight, 15 kgm. spring bal- 
ance, 2" tape, metre stick. 

Procedure: Support the bicycle so that the back wheel will 
turn freely. Measure the diameter of the rear wheel in centi- 
metres and determine its circumference. 

Count the number of teeth in the two sprocket wheels and 
determine how many revolutions the rear wheel makes for one 
complete turn of the pedals. Check this experimentally. Meas- 
ure the length of the pedal arm from centre to centre of the 
supporting axle. Determine the circumference of the circle 
traced out by a pedal in one revolution. This will give the 
distance the effort moves for one turn of the pedals. Determine 
the mechanical advantage of speed by dividing the distance of 
the resistance (circumference of rear wheel multiplied by the 
gear ratio) by the distance of the effort. The Mechanical Advan- 
tage of Force is the inverse of this. Why? 

Now attach a one-kilogram weight to the tire of the rear 
wheel so that it hangs down vertically below the outer circum- 
ference of the wheel. A piece of 2" tape placed over the outer 
circumference of the tire and supporting the weight is a good 
method of doing this. 

Hook the 15 kgm. spring balance to the centre of the pedal 
and pull upward, taking the reading of the balance when the 
pedal is in a horizontal position. Divide the resistance (1000 
gm.) by the effort. This gives the actual Mechanical Advantage 
of Force. 

Results: Tabulate all measurements and work out the actual 
and theoretical values for the Mechanical Advantage. 

Is there a big difference as between the theoretical and actual 
values? Is the bicycle an efficient machine? 

Note: If a 15 kgm. spring balance is not available the pro- 
cedure may be reversed by tieing a large weight, say 10 kgm. or 
10 lb., to the pedal and attaching a small spring balance to the 



12 

tire and pulling downwards to support the weight on the pedal. 
In this case, however, the weight of the spring balance must be 
added to its reading to determine the true value of the resistance. 

EXPERIMENT 5 

The Inclined Plane 

Object: To determine the Mechanical Advantage of the In- 
clined Plane and to calculate the efficiency of this machine. 

Reference: ''Modern Physics," Sections 216 and 217- Also re- 
view Sections 203 and 204. 

Apparatus: The Inclined Plane apparatus and car, weights, 
spring balance, metre stick, string. If the regular inclined plane 
apparatus as supplied by scientific manufacturing companies is 
not available, a smooth board 6 in. wide and five feet long and a 
model car made from a Meccano set with its bearings well lubri- 
cated may be used. 

Procedure: Set up the inclined plane at an angle of about 30°. 
Weight the car on the spring balance and attach a long string to 
the hook. Place it on the plane with a 500 gm. weight in it. 
Attach the string to the balance, pass the string over the pulley 
at the top of the plane and, applying a horizontal pull, determine 
the force required to pull the car up the slope. This force repre- 
sents the effort required to overcome the pull of gravity and the 
friction. 

Take a second reading as the car runs slowly down the plane. 
This represents the effort less the amount due to friction. The 
average of these two values gives the true force needed to over- 
come the pull of gravity down the plane. 

Measure a distance of 100 cm. along the lower edge of the 
inclined plane from the point where it contacts the table, and 
mark the distance on the edge of the plane. Measure the vertical 
height of the plane at this point from the table. 

Results: Repeat the experiment twice changing the angle of 
the plane for each trial. 

Tabulate all data as follows : 



Exp. 
No. 


Effort + 
Friction 


Effort — 
Friction 


Average 
Force 


Resistance ; 
i.e.. Weight 


Resistance 
Effort 


1. 
2. 
3. 













Exp. 
No. 


Lrength 


Height 


L/H 


Efficiency =^^X 100 


1. 
2. 
3. 











13 

Note: In the formula for efficiency given above E is the effort 
required to pull the car up the slope; i.e-, EffortH- Friction since, 
in this machine, useful work is only done w^hen the weight is 
moved up the slope. 

What is the theoretical Mechanical Advantage of the Inclined 
Plane ? What is the actual M. A. ? What is the relation between 
the Mechanical Advantage and the angle of the slope? 

EXPERIMENT 6 

Determination of Specific Heat 

Object: To determine the specific heat of aluminum or other 
suitable metal by the method of mixtures. 

Reference: "Modern Physics," Sections 269-272, with par- 
ticular reference to Section 271. 

Apparatus: Insulated calorimeter, thermometer, boiler or 
florence flask, burner, balance, set of weights, length of string, 
metal block or shot. 

Note: In this experiment the best results are obtained using 
a block of aluminum, since aluminum has a high specific heat. 
The usual method of heating some lead shot in a test tube sup- 
ported in the neck of a florence flask containing boiling water 
may, however, be used. Care must be taken in this case to see 
that the lead shot is uniformly heated and that the thermometer 
inserted in the shot measures the average temperature of the 
shot. In reading the thermometer always estimate fractions of 
a degree to the nearest tenth. A small error in the thermometer 
reading can result in a large error in the specific heat. 

Method : Tie a piece of string to the metal block and weigh it. 
Or, if lead shot is to be used weigh out about 200 gm. of shot and 
transfer to a test tube. (A piece of heavy insulated wire twisted 
around the test tube serves both as a handle and as a means of 
supporting the test tube in the neck of the florence flask for 
heating.) 

Put the aluminum in a boiler half full of water with the 
string hanging outside. Heat the boiler with a bunsen or other 
burner. Weigh the calorimeter (the inside vessel only, if it is a 
double insulated calorimeter). Fill the calorimeter 2/3 full of 
water and weigh it again. The water used should be several 
degrees below room temperature. Take the temperature of the 
steam in the boiler. Stir the water in the calorimeter gently 
with the thermometer and record its temperature. 

Now raise the aluminum block so that it hangs only in the 
steam of the boiling water for a minute or so. Record the tem- 
perature of the metal as that of the steam in which it is suspended. 
Place the calorimeter in an insulating vessel supporting it in a 
fibre ring or cotton wool packing. Quickly transfer the aluminum 
block which should be quite dry to the calorimeter and take the 
resulting temperature, moving the block up and down to ensure 
thorough mixing of the water. If lead shot is used it may be 
quickly dumped into the water and stirred with the thermometer. 



14 

Results: Tabulate all readings and weights and calculate the 
specific heat of the metal in the manner illustrated in Section 271 
of the textbook. 

Compare your result for the specific heat of the metal with 
the value given in Table 6, Appendix B, "Modern Physics." 

^ ^ 1 J. J.1 4. J.U Actual error ^ ^ ^^ 
Calculate th^ percentage error thus : ^ —r — p X 100. 

In your conclusion to the experiment indicate the most prob- 
able sources of error. 



EXPERIMENT 7 

Heat of Fusion of Ice 

Object: To determine how many calories of heat are required 
to melt one gram of ice at its melting point. 

Reference: "Modern Physics," Sections 277-279. Study the 
method of solving the problem on heat of fusion in Section 278. 

Apparatus: Insulated calorimeter, balance, weights, thermo- 
meter, ice, towel. The thermometer should be graduated in Centi- 
grade degrees and should be read carefully to the nearest tenth 
of a degree. 

Procedure: Weigh the calorimeter — inside vessel only; fill it 
with about 250cc. of water at 40° C ; weigh again. The difference 
in the two weighings will give the weight of water taken. Break 
up the ice into pieces about one inch across. Take the tempera- 
ture of the water in the calorimeter as accurately as possible 
having first placed the calorimeter in the insulating vessel. Re- 
move excess moisture from the ice by wiping it with a cloth and 
introduce it into the calorimeter taking care not to lose any of the 
water by splashing. Stir the water constantly and take the 
temperature, adding more ice from time to time until the tem- 
perature is around 5°C. Stir until the ice is all melted and take 
the final temperature accurately. 

Now weigh the calorimeter to determine the weight of ice 
which has been added. 

Results: Following the method illustrated in Section 278 of 
the textbook, calculate the heat of fusion of ice in calories per 
gram. Tabulate all weights and temperatures neatly and show 
all calculations.^ Determine the percentage error in your result. 
Indicate the chief sources of error which you think may have 
arisen in your experiment. If these include errors of manipula- 
tion, repeat the experiment and try to get a more accurate result. 

EXPERIMENT 8 

Boiling Point 

Object: To determine the boiling point of certain liquids and 
to illustrate the process of fractional distillation. 



15 

Reference: "Modern Physics," Sections 288-290. Study care- 
fully the correct method of setting up a condenser as illustrated 
in Fig. 334, page 242 of the textbook. 

Apparatus: A Liebig's condenser, distilling flask, 25 cc gradu- 
ate, thermometer, receiving flask, alcohol, 10% solution of salt 
water. 

Note: Wood alcohol, used for spirit lamps, is methyl alcohol, 
B.P. 66°C. Commercial grain alcohol is 95% ethyl alcohol, B.P. 
78 °C. Rubbing alcohol is chiefly ethyl with an admixture of 
methyl and other ingredients to ''denature" it. 

Procedure: Set up the apparatus as shown in Fig. 334, p. 242 
of the textbook. 

(a) Pour 100 cc. of tap water into the distilling flask and 
heat it to boiling. Have the bulb of the thermometer one inch 
from the surface of the water. When the thermometer remains 
steady take the temperature. If a mercury barometer is avail- 
able take the atmospheric pressure in millimetres of mercury. 
Record these readings. Boil the water for two or three minutes 
and again record the boiling temperature. 

(b) Replace the water in the distilling flask by 100 cc. of 
alcohol and determine its boiling point. Use a clean receiver for 
each distillation. 

Pour the alcohol that has distilled over back into the flask 
and add 100 cc. of water. Determine the boiling point of the mix- 
ture. Continue to boil the mixture until 25 cc. has distilled over. 
Again record the boiling temperature. 

Repeat with each of three more portions of 25 cc- of distillate, 
taking the temperature after each. Save the alcohol for future 
use. 

(c) Throw away the liquid left in the distilling flask, wash 
out flask and pour in 100 cc. of 10% salt solution. Determine the 
boiling point at intervals of three minutes as long as time permits. 

Results: (a) What is the boiling point of water? Does the 
B.P. rise with continued boiling? Refer to Table 9, Appendix B 
of the textbook. At what temperature should water boil at the 
recorded atmospheric pressure? How does this check with your 
recorded B.P. ? 

(b) What is the boiling point of pure alcohol? Is it ethyl or 
methyl alcohol ? What is the boiling point of a mixture of alcohol 
and water? How does the boiling point change for the successive 
distillate fractions? How may this be explained? 

(c) Tabulate the data from experiment (c). Account for 
any change in the boiling point of the salt solution. 



EXPERIMENT 9 

Heat of Vaporization of Water 

Object: To determine the number of heat units required to 
change one gram of water into steam at its boiling point. 



16 

Reference: "Modern Physics," Sections 291-293. Study the 
method of determining the heat of vaporization of water as 
worked out in Section 292. 

Apparatus: Steam boiler, water trap, rubber tubing, glass 
tube, balance, weights, insulated calorimeter, Centrigrade ther- 
mometer. 

Note: If a copper boiler is not available, fit up a florence flask 
half full of water, having a bent delivery tube passing through a 
one-holed rubber stopper. Heat it over wire gauze on a tripod. 

Procedure: Attach the water trap to the outlet pipe of the 
boiler or florence flask by means of rubber tubing. While the 
water is heating weigh the inside calorimeter vessel; fill it two- 
thirds full of water at about 5°C. (Snow or ice may be added to 
reduce the temperature of the tap water if necessary.) Weigh 
again to determine the weight of cold water in the calorimeter. 

Attach the glass tube to the lower end of the water trap by 
means of rubber tubing. Take the temperature of the water in 
the calorimeter reading accurately to tenths of a degree. Place 
the glass tube below the surface of water in the insulated calori- 
meter (Fig. 337, textbook), and pass a steady stream of steam 
into the calorimeter until the temperature has risen to about 
40 °C. Remove the delivery tube, stir the water in the calori- 
meter to determine its temperature. Now weigh the calorimeter 
to determine what weight of steam has condensed in the water. 

Take the temperature of the steam while the water is still 
boiling in the boiler. 

Results: Following the procedure illustrated in the textbook 
(Section 292), tabulate all data and calculate the heat of vapori- 
zation of water. 

Compare your result with that given in table 6, Appendix B, 
of the textbook, and estimate the percentage error. Indicate the 
most probable sources of error in this method. 

EXPERIMENT 10 
Dew Point and Relative Humidity 

Object: To determine the dew point and the relative humidity 
of the air in the room. 

Reference: "Modern Physics," Sections 300-306. See also 
"Elements of Physics,'' by Merchant and Chant, Sections 242-248, 
for a description of Regnault's dew-point hygrometer and the 
method of determining the relative humidity from the dew point. 

Apparatus: Either a Regnault's polished cup hygrometer or a 
highly polished metal cup, ether, ice, thermometer (Fahrenheit) ; 
either a hygrodeik or a wet-bulb thermometer prepared by tieing 
a fresh spirit lamp wick around the bulb of a Fehrenheit ther- 
mometer, the lower end of the wick dipping into distilled water. 

Note: If only Centigrade thermometers are available, refer to 
the table on p. 258, "Elements of Physics,'' by Merchant and 
Chant, for working out the relative humidity from the dew point. 



17 

Procedure: (a) Using Regnault's hygrometer. Po.ur into the 
polished cup about 5cc. of ether. Adjust the thermometer, bent 
delivery tube and straTght exit tube in the cork so that the bent 
delivery tube is below the surface of the ether but the outlet tube 
and thermometer bulb is above the ether. Attach an atomizer 
bulb to the bent delivery tube and gently force air through the 
ether so as to cause it to evaporate rapidly. Observe the drop in 
the thermometer and without breathing on the polished cup note 
the moment that a faint film of moisture appears on its surf ace.-' 
Immediately read the thermometer and record reading. Stop 
blowing air through the ether and watch the film of moisture on 
the polished cup. Record the temperature at which the film dis- 
appears. The average of these is the dew point. Repeat the ex- 
periment twice more and take the average value of the dew point. 

(b) A polished cup or tin can. may be used as follows: Fill 
the cup one-third full of water at room temperature. Add ice and 
stir with a thermometer until a film of moisture appears on the 
metal cup. Record the temperature at which the film appears and 
when it disappears. The average is the dew point. Repeat the 
experiment twice, using a fresh supply of water and ice. 

Note: It may be necessary to add warm water to make the 
film disappear from the metal surface. 

In either method (a) or (b) record the room temperature. 
Using a hygrodeik or wet-and-dry bulb hygrometer, determine 
the relative humidity by reading the two thermometers. The wet 
bulb should be gently fanned with a piece of stiff paper to obtain 
an accurate reading. Record the two readings. 

Results: (a) Having determined the dew point in Fahrenheit 
degrees, refer to Table 5, Appendix B, "Modern Physics,*' and de- 
termine the moisture capacity in grains per cubic foot at the dew 
point and also at the temperature of the room. The relative hu- 
midity may then be determined by the following formula : 

T^ 1 ,. TT -j-i™ Water Vapour capacity at dew point .^^^^ 

Relative Humidity= ^t^t-t — ^rr^ .. , r^ XIOO. 

Water Vapour capacity at room temp. 

If a Centigrade thermometer has been used, the temperature 
may be converted into Fahrenheit readings, or the table referred 
to above in ''Elements of Physics," by Merchant and Chant, may 
be used. 

From the wet-and-dry bulb thermometer readings determine 
the relative humidity by reference to Table 16, Appendix B, of 
''Modern Physics." 

Compare your results for the relative humidity of the room 
by the two methods. If there is not a fairly close agreement 
(within 5%) by the two methods, indicate in your conclusion 
which method you consider to be the most accurate. 

EXPERIMENT 11 
Lines of Magnetic Force 
Object: To map the lines of force about magnets. 
Reference: "Modern Physics," Sections 510-513. Look up. 



18 

in an encyclopedia or chemistry textbook, the method of prepar- 
ing blue print paper. This makes a good chemistry project. The 
paper may be bought at little expense from a supply house. 

Apparatus: Two bar magnets, horseshoe magnet with arma- 
ture, iron filings, sieve or perforated metal box, pan, pins, blue 
print paper, board 1 ft. square with grooves cut parallel to hold 
bar magnets and of the same depth as the thickness of the 
magnets. 

Procedure: Place a bar magnet in the grooved board in a part 
of the room where the light is subdued. Pin a sheet of blue print 
paper (9 x 11 in.) with the sensitive side up on the board so that 
the bar magnet is below the centre of the paper. Sprinkle iron 
filings in a thin layer evenly over the surface of the paper. Tap 
gently with the fingers until the filings arrange themselves in the 
direction of the lines of force. Without disturbing the arrange- 
ment of the iron filings, hold the board so that the paper is ex- 
posed to direct sunlight for about five minutes- At the end of this 
time the paper should have acquired a brownish colour. Remove 
the pins, shake off the filings into a pan, and develop the print by 
washing it in water until all the yellow colour has disappeared. 

Spread the blue print on a pane of glass to dry, face down. 

Repeat the experiment with two bar magnets placed with 
like poles adjacent, with unlike poles adjacent, and with a horse- 
shoe magnet. 

Results: When the blue prints are dry, label each, trim them 
to a suitable size and preserve them in your notebook. Compare 
the results with the diagrams shown in your textbook. Are there 
any irregularities in the lines of force shown on your blue prints ? 
Comment on the possible cause of these. 

Note: If time does not permit each group to do all of these, 
they may be divided up among the groups and the results put on 
display for the whole class to study. Other arrangements, such 
as two magnets placed at right angles in the form of a cross, or 
three bar magnets forming a triangle, or a magnet with a soft 
iron ring to illustrate shielding may be tried. 

EXPERIMENT 12 

The Voltaic Cell 
Object: To set up a simple voltaic cell and to study its action. 
Reference: "Modern Physics," Sections 545-550. 

Apparatus: A simple demonstration cell, consisting of a glass 
jar with removable clamps to support the elements, two zinc 
strips, copper strip, carbon rod, D.C- voltmeter (1-15 volts or 
lower) Daniell cell, amalgamating fluid. No. 18 insulated copper 
wire. 

Note: The amalgamating fluid may be prepared in the chem- 
istry lab. by dissolving 5 cc. of mercury in aqua regia (60 cc. of 
nitric acid mixed with 200 cc. of hydrochloric acid) . 



19 

Procedure: Prepare some diluted sulphuric acid, 1 part acid to 
20 parts water; fill the glass jar one-third full with the acid and 
place a strip of zinc in it. What gas is given off? Complete the 
equation: Zn4-H2S04 

Note the colour of the zinc after a minute or two. What im- 
purity in the zinc causes this appearance? (See Section 549, 
textbook.) What is meant by local action and how is it related 
to this impurity? 

Dip one end of the zinc strip (2 or 3 in. of it) in the amalga- 
mating fluid. Leave it for one minute, then remove, rinse and 
wipe dry. Describe its appearance. 

Now put the amalgamated zinc strip in the sulfuric acid. 
How does its behavior compare with the previous action of the 
zinc strip? Explain the advantage of coating the zinc with 
mercury. 

Remove the zinc strip from the acid, wash it and place it in 
a beaker or in the sink. Avoid spilling or splashing the acid ; it is 
very corrosive. 

Place a copper strip in the acid. Is there any action? Re- 
peat using a carbon strip. Any action? 

While the carbon is still in the acid, place the amalgamated 
zinc strip also in the acid but not touching the carbon. Is there 
any action visible when the cell is on open circuit? Attach the 
carbon and zinc strips to the terminals of the demonstration cell 
and attach the terminals to the voltmeter using the copper wire. 
Observe the action of the cell and note the strip from which hy- 
drogen gas rises. Record this. Record also the reading of the 
voltmeter. This is the E.M.F. of the cell. 

Short-circuit the cell by joining the two terminals by a short 
length of heavy copper wire. Leave it for a few minutes, then 
remove the shunt wire and again read the voltmeter. Record 
this. What is the appearance of the carbon strip now? What is 
the name for this effect? 

Now lift the strips from the solution, wipe off the bubbles of 
gas and replace in the solution. Read the voltmeter and record. 
Does the voltage return to its original value ? Again short-circuit 
the cell with the shunt wire until it is polarized. Add a few cry- 
stals of sodium or potassium dichromate to the sulfuric acid and 
stir. What is the effect of the dichromate crystals on the read- 
ing of the voltmeter? What kind of an agent is potassium or 
sodium dichromate? What is the effect on hydrogen? What is 
the essential property of a good depolarizer? 

If time permits, set up the Daniell cell as follows : In the por- 
ous jar pour dilute sulfuric acid (1 of acid to 20 of water) . Place 
an amalgamated zinc strip in the acid. Place the porous jar in 
the glass battery jar and fill the latter with a saturated solution of 
copper sulfate to the same depth as the acid in the porous jar. 
Insert the copper plate in the solution of copper sulfate- Allow 
time for the liquid to soak through the porous vessel and deter- 
mine the E.M.F. of the cell with a voltmeter. Record the reading. 
Short-circuit the cell with the copper wire as before for two min- 
utes and again record the voltage. Does this cell polarize? 



20 

Remove the copper plate and examine it. Is there a deposit 
on its surface? What is it? The action at the positive plate is 
represented by this equation : ; 

H2 + CuS04=H2S04+Cu. 

If the Daniell cell is to be left standing for future use con- 
nect it in series with a 40 ohm resistance. 

Results: Tabulate all observations and readings and summar- 
ize your conclusions as to the cause and remedy for (a) Local 
action, (b) Polarization in the voltaic cell. 

Draw a diagram of the Daniell cell and explain its operation. 

EXPERIMENT 13 

Grouping of Cells 

Object: To study the different ways in which cells may be 
grouped and to determine the advantage of one method over 
another. 

Reference: "Modern Physics/* Sections 555-559. Study the 
rules which apply to (a) cells in series, and (b) cells in parallel 
as listed in Section 558. 

Apparatus: Three Daniell cells, voltmeter, ammeter, resist- 
ance coils. No. 18 insulated copper wire. 

Note: A gravity cell is a form of Daniell cell that may be 
used for this experiment. The simple voltai<: cell is not suitable 
owing to polarization. Three dry cells may be used but since their 
internal resistance is very low, it may not be easy to show the 
advantage of parallel connections for certain resistances with 
them. 

Procedure: Connect a Daniell cell to the voltmeter by means 
of No. 18 copper wire and determine the E.M.F. Disconnect the 
voltmeter and connect in an ammeter and determine the amper- 
age without other external resistance. Record the voltage and 
amperage. Connect the cell to a resistance of about 5-30 ohms 
and determine the amperage. 

Connect three Daniell cells in series (Fig. 607, textbook) and 
test the combined E.M.F. with a voltmeter connected across the 
outside terminals of the series group. Record the voltage. 

Now connect the three cells in series with the ammeter and 
a 40 ohms resistance. Record the amperage. Note that the 
external resistance of 40 ohms is large compared with the com- 
bined internal resistance of the cells. 

Now connect the three cells in series directly to the ammeter. 
Record the amperage. In this case the external resistance, that 
of the ammeter and connecting wires, is quite low, less than the 
internal resistance of the cells. 

Repeat the procedure using the three cells in parallel (Fig. 
609, textbook). Record the voltage and amperage alone, and 
when the parallel group of cells is connected with the 40 ohm 
resistance in series with the ammeter. 



21 



Results: Tabulate the data as follows 



Grouping 


Voltage 


Maximum 
current 


Current with 
40 ohms R. 


Single cell 








Three cells 
in series 








Three cells 
in parallel 









From the tabulated results indicate which method of group- 
ing gives the maximum current: (a) when the external resist- 
ance is large compared to the internal resistance, (b) when the 
external resistance is smaller than the internal resistance. 



EXPERIMENT 14 

Ohm's Law 

Object: To determine the resistance of an unknown resistor 
by the application of Ohm's law. 

Reference: "Modern Physics," Section 553 and the first part 
of Section 619. For a more detailed explanation of Ohm's law as 
used for the determination of the resistance of a conductor, read 
"Elements of Physics," Sections 535-536. Note Fig. 610 in "Ele- 
ments of Physics" for the method of connecting the apparatus 
for this experiment. 

Apparatus: Ammeter, voltmeter (these should be graduated 
in tenths) , rheostat or resistance box, battery of 5 or 6 volts, No. 
18 wire for connections, or Pietenpol connectors, a length of re- 
sistance wire of unknown resistance as supplied by your teacher. 
This may be of any value between one ohm and 30 ohms. 

Procedure: Connect in series the following: Battery, knife 
switch, rheostat or variable resistance box, unknown resistor, 
ammeter. Across the ends of the unknown resistor connect in 
parallel the voltmeter. Set the rheostat so as to include only a 
few turns of wire, or, if a resistance box is used, set it at one ohm. 

Close the knife switch and immediately take the readings of 
both voltmeter and ammeter, reading to the nearest hundredth of 
an ampere or volt. Note: If the instruments are graduated in 
tenths, this will involve estimating the fractions of a division by 
judging with the eye the approximate fraction and expressing it 
as tenths. This will give the second decimal point in your read- 
ing. The knife switch should not be left closed for more than a half 
minute at a time, as the resistors will heat up and the resistance 
change while you are reading the instruments. Record the read- 
ings in a table as shown below. With the knife switch open, 
change the position of the rheostat or set the variable resistance 



22 

at 2 ohms and, closing the switch, again take readings of the am- 
meter and voltmeter. Repeat the experiment with a gradual in- 
crease in the resistance of the variable resistance taking readings 
of the ammeter and voltmeter each time. Obtain five sets of 
readings. 

Results: Tabulate all data as follows: 



Exp. No. 


Voltmeter 
Reading 


Ammeter 
Reading 


Resistance Tj_ E 
in ohms I 











Is the value for R, i.e., the unknown resistance, constant? 

Take the average value of the ^ve trials. If the material of 
the unknown resistance wire is known, measure its length and 
diameter (micrometer screw gauge) expressed in feet and mils 
and, applying the formula on p. 442 of ''Modern Physics,*' calcu- 
late the resistance in ohms. Compare this value with the method 
of your experiment. Which do you consider the more accurate? 



EXPERIMENT 15 

The Wheatstone Bridge 

Object: To determine the resistance of a conductor by the 
method of Wheatstone's Bridge. 

Reference: ''Modern Physics," Section 619. Study Fig. 683, 
p. 492, for the method of connecting the apparatus. 

Apparatus: A slide-wire Wheatstone bridge, dry cell, D'Ar- 
sonval type of galvanometer, resistance box, an s.p.s.t. knife 
switch, connectors and an unknown resistance to be determined. 

Procedure: Connect up the apparatus in the manner illus- 
trated in Fig. 683 of the textbook. Use short lengths of No. 18 
wire for the connectors. Place the resistor to be determined at 
X; connect in the adjustable resistance box at R. Connect the 
galvanometer across the points DK, using a short wire at D but 
a piece about 50 cm. long from the galvanometer to K. Connect 
the dry cell across the ends of the German silver wire AC, insert- 
ing a single-pole-single-throw switch between the battery and 
the wire. 

Note: This is not shown in Fig. 683, but it is advisable so that 
the battery circuit can be opened when readings are not being 
taken, thus avoiding wastage and overheating of the resistance 
wires. 



23 

Slide the contact key to the 50 cm. mark and remove the 100- 
ohm plug from the resistance box. This introduces a resistance 
of 100 ohms at R. Now press down the key K and observe the 
needle of the galvanometer. Note: Make sure the galvanometer 
needle is able to turn freely and that the coil to which it is at- 
tached does not touch at any point as it swings. The reading 
should be zero when no current is passing through the galvano- 
meter. The needle will probably jump violently when the key K 
is depressed. Adjust the resistances in the box R, either more or 
less until the motion of the needle is no longer violent and it 
moves over a few degrees of the scale. 

Note: The plugs in the resistance box should be pressed in 
firmly to make good contact each time they are replaced. 

To make the final adjustment so that the bridge is "bal- 
anced" and the galvanometer registers zero deflection, move the 
sliding key K to right or left as may be required until, on depress- 
ing the key, the galvanometer registers zero. 

Read the value of the resistances in the resistance box and 
the exact ix)sition of the key K to the nearest millimetre at the 
point where it touches the wire. Record these. 

Results: Tabulate the data and, using the method explained 
on p. 492 of the textbook, work out the value of the unknown re- 
sistor X in ohms. 

Knowing the dimensions of the resistor, i.e., its length in 
feet and its diameter in mils, determine the value of K in the 
formula for resistance. 






; 



Compare this value with the accepted value for the material 
of the resistor as given in Table 15, Appendix B, of the textbook. 

Repeat the experiment using the dry cell, only in this case 
connect a low resistance shunt across the terminals of the am- 
meter. Remember your ammeter is a valuable instrument. Pro- 
tect it from an overload. 

Results: Tabulate all results as follows: 



Type of 
cell used 


E 


El 


I 


Ext. Res. 
R 


Int. Res. 
r 















Compare the results as given by the two methods. Which is 
more accurate? Give reasons. 



24 

EXPERIMENT 16 

Internal Resistance of Cell» 

Object: To determine the internal resistance of a cell (a) by 
Ohm's law method, (b) by the reduced deflection method. 

Reference: "Modern Physics," Section 556. 

Apparatus: A Daniell or gravity cell, voltmeter and am- 
meter, both graduated in tenths, knife-switch, resistance box, dry 
cell. 

Procedure: Connect the gravity of Daniell cell in series with 
a switch, ammeter and resistance box. Connect a voltmeter 
across the terminals of the cell. See Fig. 605, p. 442 of textbook. 

With the switch open read the voltmeter. Record this read- 
ing as E volts. 

Since this cell has a high internal resistance, it is not neces- 
sary to put any other resistance in the external circuit. The re- 
sistance box may therefore be set at zero and the switch closed. 
Read the voltmeter and ammeter. Record the ammeter reading 
(I), and the voltmeter reading (E ). 

Calculate the resistance of the cell by applying Ohm's law as 
follows : 

E— El 

^ — r- 

Repeat the experiment with the dry cell in place of the- 
Daniell cell. In this case a small resistance must be introduced 
in the resistance box before closing the switch. 

Note: The current from a dry cell is too heavy to be put 
through the ammeter without some resistance in the circuit. Do 
not bum out your ammeter. Have your teacher check your ap- 
paratus before proceeding. 

(b) Reduced deflection method. Connect the Daniell cell, 
switch, ammeter and the resistance box in series. With a zero 
resistance in the resistance box, close the switch and take the 
ammeter reading. Record this. Now remove plugs from the 
resistance box until enough resistance has been introduced to re- 
duce the ammeter reading to exactly one-half. Record the re- 
sistance of the resistance box. This is a measure of the internal 
resistance of the cell. 

EXPERIMENT 17 

Magnetic Field about a Conductor 

Object: To perform Oersted's experiment and to study the 
nature of the magnetic field about a wire carrying a current. 

Reference: ''Modern Physics," Sections 561-564. 

Apparatus: A galvanoscope having one turn, several turns 
and many turns, each with their respective binding posts, Pieten- 
pol connectors, 2 dry cells or storage battery, Daniell cell, knife 



25 

switch, four small compasses, one large demonstration compass 
needle, sheet of stiff cardboard 1 ft. square, length of bare No. 12 
or No. 14 copper wire. 

Procedure: (a) Test Oersted's experiment as illustrated in 
Fig. 611 and Fig. 612, using the Daniell cell and a demonstration 
compass needle. Test the right-hand rule for determining the 
direction of the current. Place the wire above and below the 
needle and reverse the connections on the Daniell cell, testing the 
rule each time. 

(b) Place the galvanoscope on the bench so that the single 
wire is parallel to the compass needle as it points towards the 
magnetic North pole. Turn the compass so as to bring the zero 
point directly below the North pole. Connect the Daniell cell with 
the knife switch in series with the terminals of the single gal- 
vanoscope wire so that when the switch is closed the current will 
flow from South to North over the needle. 

Close the switch and note the direction in which the North 
pole is deflected and the number of degrees on the compass scale. 
Reverse the connections of the Daniell cell so that the current 
flows from North to South. Close the switch and read the number 
of degrees of the angle of deflection. Record these readings. With- 
out changing the position of the galvanoscope on the bench, 
repeat the experiment with the compass needle under the few 
turns of wire. Record the angle of deflection for both directions 
of the current flow. 

Repeat again with the many turns of wire. Record the 
angle of deflection of the needle. 

(c) Pass the heavy copper wire through a hole in the sheet 
of cardboard, supporting the latter in a horizontal position by 
means of a wooden clamp. Note: An iron retort stand is fre- 
quently magnetized and may give erroneous results. 

Connect the ends of the copper wire to two dry cells or a 
storage battery and the knife switch in series using No. 18 wire. 
Place the four small compass needles around the wire in the man- 
ner illustrated in Fig. 613 of the textbook. 

Close the switch and observe the position of the compass 
needles. Reverse the connections so that the current flows in the 
opposite direction, close the switch and again observe the position 
of the needles. Apply right-hand rule No. 2 on p. 452 for both 
tests. 

Results: Tabulate the results of experiment (b) and state the 
effect of increasing the number of turns of wire. 

Draw diagrams to illustrate the positions of the compass 
needles in experiment (c) : (i) when there is no current, (ii) 
when the current flows upward, (iii) when the current flows 
downward. 

EXPERIMENT 18 

Efficiency of Lamps 

Object: To determine the efficiency of various lamps and to 
compare series and parallel wiring for lamps. 



26 

Reference: "Modern Physics," Sections 599 and 600. 

Apparatus: A.C. voltmeter, 0-150; A.C. ammeter, 0-10; 3 40- 
watt lamps, 1 25-watt, 1 60-watt, 1 100-watt lamps ; 16-c.p. and 
32-c.p. lamps ; a lamp board to be constructed as follows : On a 
piece of 3-ply wood, 6" x 3', set out three lamp sockets about 8" 
apart and towards one end of the board. Screw them to the 
board and connect them, in parallel (Fig. 654), with a heavy in- 
sulated electrician's wire. Remove only enough of the insulation 
to make good contact on the sockets. Spread the rest of the wire 
along the board and fasten the ends to two terminal binding 
posts, well insulated, at the extreme end of the board. On one 
wire insert a lamp socket to take a fuse plug and a single-pole- 
single-throw porcelain based knife switch. Cut the wire at two 
points equally spaced between the terminal post and the first 
lamp socket, and insert the fuse socket and the knife switch in 
series with each other. On the other wire insert another lamp 
socket to take a second fuse plug and two binding posts for at- 
taching an ammeter. You should now have in series going from 
one binding post to the other, a lamp socket (A) , a knife switch, 
a group of three lamps (B, C and D) in parallel, two binding 
posts (M and N), and another lamp socket (E). 

Procedure: (a) Connect the terminals of the lamp board to 
an A.C. 110- volt outlet by means of a lamp cord and plug. Insert 
two 6-ampere fuse plugs in sockets A and E. These are to pro- 
tect the measuring instruments. 

Place a 25-watt lamp in socket B. Connect an ammeter 
across M and N and a voltmeter across the terminals of the lamp 

B. Close the switch and read the ammeter and voltmeter. Re- 
cord the readings in a table as shown below. 

Do the same for the 40-watt, the 60-watt, the 100-watt, the 
16-c.p. carbon and the 32-c.p. carbon lamps. 

Record all readings. Note: Open the knife switch each time 
you replace a lamp in socket B. 

(b) Place a 40-watt lamp in B. Take readings and record. 
Place another 40-watt lamp of the same make in C. 

Close the switch and read the ammeter and voltmeter. 
Open the switch and transfer the voltmeter to the terminals 
of lamp C. Record readings. 

Insert a third identical 40-watt lamp in socket D. Close the 
switch and read the ammeter and voltmeter, changing the latter 
to D after checking to see if there is any change in the reading at 

C. Record all readings. 

(c) Remove the fuse plug nearest to the ammeter and insert 
a 40-watt lamp in its socket (E) . Remove lamps from C and D. 
You now have lamps in B and E in series. Close the switch and 
determine the ammeter reading and the voltage across each lamp 
separately and across the two together. Record all readings. 



27 

Results: Tabulate the data of experiment (a) as follows, tak- 
ing a 25-watt lamp to have a 20 c.p., a 40-watt lamp to have a 32 
c.p., a 60-watt lamp to have a 50 c.p., and a 100-watt lamp to 
have 100 c.p. : 



Kind of 
Lamp 


Volts 


Amps 


Watts 
Used 


Rated 
wattage 


Candle 
Power 


Watts 

per 
candle 


Cost per 

candle 

per hour 



















Cost of electricity to be reckoned at 10c per kilowatt-hour. 
Tabulate the results of experiments (b) and (c) thus: 



No. of lamps 


Connection 


Voltage 


Amperage 


Single 
Two 
Three 
Two 


Parallel 
Parallel 
Series 







What are the advantages of parallel wiring for lamps over 
series wiring? 



EXPERIMENT 19 
Induced Currents 

Object: To study induced currents. 

Reference: ''Modern Physics,'' Sections 620-623 and 642. 

Apparatus: Primary and secondary coils with core, or Gilley's 
induction study outfit, or home-made coils as in figure 718 of 
text ; bar magnet small enough to enter larger coil, sensitive gal- 
vanometer, dry cell. 

Procedure: (a) Connect the larger coil to the galvanometer. 
Hold the magnet about six inches away from the coil with the 
north pole nearer to it. Thrust the magnet quickly into the coil, 
hold it there a moment, pull it out. Note the direction of any 
deflection of the galvanometer needle. Work out the direction 
of flow of the currents in the coil. Work out the polarity of the 
end of the coil nearer the magnet for each current. 



Repeat using the South pole of the magnet. 
Record your results as follows : 



28 



Magnet 
movement 


Deflection 

of needle 

(right or 

left) 


Direction of current in 

coil. (Clockwise or 

counter clockwise in 

face nearer the magnet) 


Polarity of 

coil face 

nearer 

magnet 


N Pole 
Toward coil 








Stationary 
in coil 








Away from 
coil 








SPole 
as above 









(b) Connect a dry cell to the smaller coil. Use this coil in 
the same manner as you did the magnet in (a) , pushing it in and 
out of the larger coil. Note the movements of the galvanometer 
needle. 

Repeat with the core in the smaller coil. 

Repeat with the current reversed. 

Record in a manner similar to that used in (a) , showing in 
the last column whether the induced current is in the same or the 
opposite direction to the current in the primary. 

What was the effect of putting the core in the smaller coil? 
Does the induced current always oppose the primary 
current? 

(c) Disconnect one wire from the cell. Place the smaller 
coil inside the larger. Touch the disconnected wire to its binding 
post ; remove it after holding it there a moment. Note any move- 
ment of the galvanometer needle while the circuit is being closed 
and opened. Repeat with the core in the smaller coil. 

Record your results as in (a) and (b). 

Does any current flow in the secondary while a current flows 
steadily in the primary? 

Which induces the larger current, making or breaking a 
circuit? 

What is the effect of the core? 

Does the induced current always oppose the change which 
causes it? 



EXPERIMENT 20 

The Electric Motor 
Object: To study the action of a simple electric motor. 
Reference: "Modern Physics," Sections 635-640. 
Apparatus: St. Louis type demonstration motor, dry cell. 



29 

Procedure: Remove the bar magnets from their holders and 
connect the dry cell to the armature terminals. Turn the arma- 
ture by hand through a complete circle and test the polarity of 
each end of the armature by means of a bar magnet (law of mag- 
netic poles) at several points in the circle. Note the change in 
polarity as the two segments of the commutator move from one 
brush to the other. Draw diagrams as in Figs. 708-710, p. 508 
of textbook, and indicate the polarity in different positions. 

Now insert the bar magnets so that a North pole of one and a 
South pole of the other are close to the armature. Connect the dry 
cell as before and set the armature rotating. 

Study the effect of separating the magnets further apart on 
the speed of the motor, and the effect of using two like poles. Re- 
verse the connections of the dry cell. Note the direction of rota- 
tion of the motor. Now disconnect the dry cell, remove the bar 
magnets and insert the electro magnet. Connect the dry cell, the 
armature terminals and the field magnet all in series. Note the 
direction of rotation of the armature. Change the connections on 
the dry cell so as to reverse the direction of the current. Note the 
direction of rotation now. Is there any change? Why is this 
different from the effect with permanent field magnets? 

Now connect the armature, the field magnet and the dry cell 
in parallel. Again try the effect of changing the connections on 
the dry cell so as to reverse the direction of the current. How 
does this affect the direction of rotation of the motor? 

Results: Draw diagrams to show the connections, the direc- 
tion of current flow and direction of rotation, also polarity of the 
field magnets for each of the three types used, i.e., (i) using per- 
manent field magnets, (ii) series wound motor, (iii) shunt 
wound motor. 



CHEMISTRY. 2 



DIRECTIONS TO STUDENTS 

1. Before coming into the laboratory to perform an experiment, 
study the directions outlined here in the procedure. Be sure 
that you understand what you will be doing, and why. Do not 
attempt an experiment the relevant theory, of which you have 
not already studied. 

2. Question each step as you proceed. Learn the names of the 
chemicals and apparatus. Examine materials used ; and also 
the precipitates formed, and other products, so as to be able to 
identify them as your work progresses. 

3. Follow the directions closely and use great care when flames, 
acids, and bases, and inflammable liquids are employed. 

4. Use small quantities of chemicals. Larger quantities fre- 
quently retard the progress of the experiment. 

5. Record all results of your experiment and make liberal use of 
diagrams (sectional) in making your report. These diagrams 
should be neatly drawn and neatly labelled. 

6. Be sure your apparatus is clean. After completion of the ex- 
periment, clean all apparatus and leave the desk in a dry and 
tidy condition. 

7. Learn the capacity (in cc.) of an ordinary test tube so as to 
be able to measure out approximate volumes (10 cc.) without 
loss of time. 

8. In case of accident, call your instructor at once. 

In the following exercises — 

^'Result?" means to make a written record of your obser- 
vation. 

Interpret "Odour?" ^'Equation?" also in written form. 

Unless the word "dilute" is used before an acid, the concen- 
trated acid is to be used. 

Bracketed numbers refer to related material in the author- 
ized textbook. 

LIST OF EQUIPMENT: CHEMISTRY 2 

This list makes adequate provision for practical work. At 
the present time, however, it may be difficult to get some of the 
apparatus and materials listed ; and it may be necessary for in- 
structors to improvise equipment and substitute other materials. 

SUPPLIES FOR SIX STUDENTS 

The following is a list of the supplies needed for six students 
working in three groups of two each or for three students work- 
ing singly. A reasonable margin has been allowed for break- 
ages. It includes several pieces of equipment which are also re- 



31 

quired for Chemistry 1. The list is divided under sub-headings 
as follows : 

A. — Apparatus required for all groups. It is desirable that 
this be issued at the beginning of the year, especially if 
drawers and cupboards lock. 

B. — (1) Apparatus for common use of several groups. This 
should be considered a minimum list. 
(2) Additional and more extensive apparatus which 
should be included for large classes or even for 
small ones if circumstances permit. 

C. — Chemicals. 

D. — Materials which may be obtained locally. 



A. — ^Apparatus required for all groups. 

(Quantities are sufficient for three groups.) 

Note: "Pyrex" or some good resistance glass is recommneded for 
all glassware. Although it is more expensive, it is so much more 
durable that its use results in greater economy being effected. 

Description Quantity 

Alcohol lamps, 4 oz. at least (or bunsen burners with 
the fish tail attachments if gas is available) 3 

Beakers, low form with lip, 250 cc 6 

Beakers, low form with lip, 150 cc 6 

Blowpipes, 8-10 inches, brass recommended 3 

Blue Glasses, 2" x 1" 3 

Bottles for collection of gases, etc., at least 8 oz., low 

form 12 

Bottles for reagents, glass stoppers, at least 4 oz 30 

Burettes, 50 cc, Mohr type for pinchcock recommended 3 
Burette, fittings for above, burette tip with rubber tub- 
ing and pinchcock 3 

Filter papers, 5" in dia., coarse for rapid work 1 pkg. 

Flasks, Erlenmeyer, 300 cc. No. 6 top 4 

Rubber stoppers, two holes, No. 6 for the above flasks 4 

Funnels, glass, 65 mm. dia., 150 mm. stem 3 

Glass tubing, 6 mm., ext. dia 1/8 lb. 

Graduates, 100 cc to show 1 cc. 3 

Graduates, 10 cc. 3 

Non-combustible rods for flame tests (or see B list) .... 3 

Pipettes, 10 cc, (Note: 3 burettes may be used in- 
stead) 1 

Pneumatic troughs, galvanized iron or glass, about 
7"xl0"x5" 3 

Retorts, 125 to 250 cc, glass for making bromine 3 



32 

Description Quantity 

Retort stands, base, about 31/2" x 6I/2" ' 3 

Retort stands, rings— large 3%" dia. inside; small, 

21/2" dia 3 each 

Retort stands, fixtures, burette clamp 3 

Rubber tubing, 3/16" dia. inside for generators and 

connections 8 ft. 

Test Tubes, 16 mm. dia. outside, 150 mm. long 30 

Test Tubes, 20 mm. dia. outside, 150 mm. long (prep. 

of O2) 5 

Rubber stoppers, 1 hole, size No. 2, large end, 20 mm. 3 

Test Tube brush, bristle end 3 

Test Tube racks, large enough to hold 10 tubes upright 

rec. 3 

Thistle tube, stem, 6 mm. dia. outside 4 

Tubes, combustion, dia. inside, about 15 mm., length 

5-12" 3 

Wire gauze squares, iron or copper, 4" side 3 

B. — (1) Apparatus for the common use of several groups. 

Description Quantity 

Balance, with weights, capacity, 100 to 150 grams, sen- 
sitivity, 5 mg. (Note: If balance is to be used for 
Physics 2 as well, one of greater capacity should be 

obtained) 1 

Bottles, reagent, glass stoppers, 500 cc. capacity 10 

Beaker, low form with lip, pyrex, capacity, 600 cc 1 

Barometer, graduated in Metric scale, aneroid is re- 
commended'. 1 

Files, triangular, 5" 3 

Funnel, glass, dia. at least 80-100 mm. 1 

Mortar and pestle, about 5 inches in dia 1 

Thermometer, Centigrade, range, — 10° — 110°, solid 
stem 1 

Platinum wire, length 3" long sealed in glass tubing.. 6 in. 

Flask, Erlenmeyer, 500 cc, with generator fittings if 

Kipp's Apparatus is not available (See below) 1 

Furniture: (1) Tables for students* practical work in the labora- 
tory. Suggestions re. construction: height, 36 inches; 
width, 4 ft.; length, depends on requirements and space 
available. Each group needs a space about four feet wide 
and half the width of the table ; this gives about eight square 
feet. A shelf along the centre of the table is convenient for 
reagent bottles. Drawer and cupboard space for storing 
apparatus in students' tables is needed and should be added 
when finances will permit. If they are constructed with 



33 

locks, groups may be given sets of apparatus at the begin- 
ning of the year and held responsible for it throughout the 
year. (2) Cupboards, which will lock, are needed for stor- 
ing chemicals and apparatus. (3) Demonstration table for 
instructor, specifications, see above, width 21/^ to 4 ft. 



B. — (2) Additional and more extensive apparatus which 
should be included for large classes. 

Kipp's gas generator, capacity of generating chamber, 500 cc. 1 

Fume cupboard: As poisonous gases are very injurious for stu- 
dents and teacher, a fume cupboard for the preparation of 
such gases should be provided. Position, near demonstra- 
tion table in the classroom so that it may be used convenient- 
ly during instruction periods, as well as during laboratory 
periods. 

Size, at least two feet square; bottom of cupboard, 3 feet 
from floor; height, about 3^/2 f^^t, that is, top, 6% feet from 
floor. 

Ventilation: If poisonous gases are to be prevented from entering 
the room, this cupboard should be connected to the outside of 
the building by means of a pipe. If it is not feasible to do 
this through the heating or ventilating systems of the build- 
ing, an electric fan may be found to be effective. 

NOTE: Large classes will require additional quantities of the 
apparatus listed under B (1) above. 



C— CHEMICAUS. 

(For class of six, i.e., three groups.) 

NOTE: Even for classes as small as six, it will be found to be 
more economical to buy in larger quantities than those given 
below. 

Description Quantity 

Alcohol (for use in lamps) 1 pt. 

Alcohol, denatured 1 qt. 

Alum, pure powder 1 lb. 

Aluminium foil or turnings 2 oz. 

Aluminium Chloride C.P 1 oz. 

Aluminium Nitrate C.P 4 oz. 

Aluminium Sulphate C.P 2 oz. 

Ammonium Carbonate C.P 4 oz. 

Ammonium Chloride C.P 1 oz. 

Ammonium Hydroxide C.P. 1 oz. 

Ammonium Nitrate C.P 4 oz. 



34 

Description Quantity 

Ammonium Molydate C.P 1 oz. 

Ammonium Sulphate C.P 4 oz. 

Ammonium Sulphide Solution 4 oz. 

Ammonium Sulphite C.P. 4 oz. 

Ammonium Phosphate C.P. 4 oz. 

Ammonium Thiocyanate C.P 2 oz. 

Arsenious Oxide (Demon, only) , 1 oz. 

Barium Chloride C.P 4 oz.- 

Barium Nitrate C.P. 4 oz. 

Bismuth Trichloride 1 oz. 

Bleaching Powder 12 oz. 

Borax, crystals 1 lb. 

Calcium Carbonate, ppt 4 oz. 

Calcium Carbonate, marble chips 1 lb. 

Calcium Chloride C.P 4 oz. 

Calcium Hydroxide, Tech 1 lb. 

Calcium Nitrate C.P 1 oz. 

Carbondisulphide 1 lb. 

Carbontetrachloride 1 lb. 

Charcoal, animal, powder 4 oz. 

Charcoal, lumps or blocks 1 oz. 

Chloroform, Tech 1 oz. 

Cobalt Nitrate 1 oz. 

Copper filings 4 oz. 

Cupric Bromide 1 oz. 

Cupric Nitrate C.P. 4 oz. 

Cupric Sulphate, C.P., pow 1/2 lb. 

Cupric Sulphate, Tech. % lb. 

Cupric Chloride, C.P 4 oz. 

Ferric Chloride, C.P. 4 oz. 

Ferric Nitrate, C.P 4 oz. 

Ferric Sulphate, C.P 4 oz. 

Ferrous Chloride, C.P 4 oz. 

Ferrous Sulphide, granular 8 oz. 

Glucose, pure anhydrous 4 oz. 

Hydrochloric Acid, C.P 1 lb. 

Iron filings 1 lb. 

Lead Nitrate, C.P 4 oz. 

Lead Peroxide, Tech. 1 oz. 

Lead Oxide (litharge) 4 oz. 

Lead Oxide (red lead) 1 oz. 

Lithium Chloride 1 oz. 

Litmus, Best qual., gran. 1 oz. 

Litmus paper, blue, vial of 100 strips 

Litmus paper, red 

Magnesium ribbon 1 oz. 

Magnesium Carbonate, heavy 4 oz. 

Magnesium Chloride, C.P. 4 oz. 

Magnesium Nitrate, C.P 4 oz. 



35 

Description Quantity 

Magnesium Sulphate, C.P 8 oz 

Manganese Dioxide, C.P 4 oz! 

Manganese Dioxide, Tech. 1 ib* 

Mercury metal i qz*. 

Mercuric Chloride, C.P ........".. 1 oz! 

Mercuric Nitrate, C.P 1 oz! 

Mercurous Nitrate, C.P. 1 oz! 

Methyl Orange i/^ oz! 

Nitric Acid, C.P 1 lb. 

Nickel Chloride 1 ©z! 

Phenolphthalein 1 oz. 

Portland Cement 4 oz! 

Potassium Bromide, C.C. or U.S.P 4 oz! 

Potassium Carbonate, C.P 4 oz. 

Potassium Chlorate, C.P., pow. 4 oz. 

Potassium Chloride, C.P 4 oz. 

Potassium Chromate, C.P ,. 4 oz. 

Potassium Ferricyanide, C.P. 1 oz. 

Potassium Ferrocyanide, C.P 4 oz. 

Potassium Iodide 1 oz. 

Potassium Nitrate, C.P. 4 oz. 

Potassium Permanganate U.S.P 4 oz. 

Potassium Phosphate, C.P 4 oz. 

Potassium Sulphate, C.P 4 oz. 

Potassium Sulphite, C.P 4 oz. 

Silver Nitrate 1 oz. 

Sodium Acetate Anhy 1 lb. 

Sodium Bicarbonate, C.P 1 lb. 

Sodium Carbonate, Tech., pow. 8 oz. 

Sodium Chloride, C.P 1 lb. 

Sodium Hydroxide, C.C. sticks or pellets 4 oz. 

Sodium Nitrate, C.P., pow. 1 lb. 

Sodium Peroxide, pow. 4 oz. 

Sodium (Disodium) Phosphate, C.P. 4 oz. 

Sodium Sulphate, C.P 4 oz. 

Sodium Sulphite, C.P 4 oz. 

Sodium Sulphide, C.P 4 oz. 

Sodium Thiosulphate 4 oz. 

Starch, corn 4 oz. 

Strontium Chloride, C.P 1 oz. 

Sulphuric Acid, C.P 1 lb. 

Zinc, C.P. (low in As.), gran 1 lb. 

Zinc Chloride, C.P 2 oz. 

Zinc Nitrate, C.P 4 oz. 

Zinc Sulphate, C.P 4 oz. 

Zinc Sulphide, Tech 4 oz. 

NOTE: The above list includes small quantities of a variety of 
salts which may be used as "unknovnis** in Exercises 51 
and 52. 
Equivalents: 28.3 grams=l oz.; 1 pound=453.6 grams. 



36 

D. — Materials which may be obtained locally. 

(For class of six, three groups.) 

Candles, paraffin, for demonstration 2 

Clay, well pulverized ^A lb. 

Clock spring, 1/8" wide 1 ft. 

Commercial soap, 3 or 4 cakes. 

Copper sheet, medium gauge, 17 sq. in. cut into 

strips about 3" x 3/8". 
Zinc sheet or new galvanized iron, same as above. 

Distilled water 1/2 gal. 

Finger bandaging, 2" wide 1 yd. 

Glass (window) cut in 3" squares 6 squares 

Honey 1 oz. 

Iron nails, bright, 11/2-2" 6 

Lard or other fat 1 lb. 

Lime (quicklime) 1 lb. 

Molasses, black 2 oz. 

Red calico '. 1/8 yd. 

Sugar, cane or beet 28 gm. 

Wooden splints^ — 6"-8" long 2 doz. 

Oatmeal 1 oz. 

Vegetable oil (olive, peanut, etc.) 1 oz. 

Vinegar 1 oz. 



LIST OF EXPERIMENTS 

N.B. — References are made to chapters and pages of the 
Textbook. 



1. BROMINE AND IODINE 

(Chapter 10) 

Bromine and iodine may be prepared by the students (p. 
159), but it is suggested that these and chlorine water (p. 150) 
be prepared in advance by the teacher. Sodium salts may be 
substituted for potassium salts in this exercise. 

Apparatus — Test tubes and rack. Burner. 

Materials — Potassium chloride. Potassium bromide. Po- 
tassium iodide. Chlorine water. Bromine water. Silver nitrate 
solution. Ammonium hydroxide. Sulphuric acid (1 of acid to 2 
of water). Manganese dioxide. Carbon disulphide or carbon 
tetrachloride. Alcohol. Iodine crystals. Starch. Tincture of 
iodine. 

Tests for a chloride, a bromide and an iodide. 

1. To a concentrated solution of each of (1) potassium brom- 
ide, (2) potassium iodide, in separate test tubes, add a few cc. of 
chlorine water (p. 162). Colours? Equations? 



37 

2. Half fill three test tubes with a dilute solution of a chlor- 
ide, a bromide and an iodide, respectively. To each add a few 
drops of silver nitrate solution (p. 156). Colours? Equations? 

3. After allowing the precipitate formed in (2) to settle, 
pour off the supernatent liquid. To each precipitate add about 5 
cc. of ammonium hydroxide. Shake. Result? 

4. Prepare a precipitate of silver chloride and let stand for 
a few minutes in a strong light. Result? 

5. Into each of three test tubes pour about i/^ cc. of sul- 
phuric acid. (If not previously prepared by the teacher, this acid 
can be prepared by adding, slowly and carefully, 1 part of sul- 
phuric acid to 2 parts of water) . Into the first test tube pour 
about % cc. of a mixture of potassium chloride and manganese 
dioxide. To the second add a similar amount of a mixture of 
potassium bromide and manganese dioxide, and to the third add 
a mixture of potassium iodide and manganese dioxide. Warm 
each test tube gently if no reaction is visible (p. 159). Colours? 
Equations ? 

Solubility of halides. 

6. Dissolve a pinch of (1) potassium bromide in 5 cc. of 
water, and of (2) potassium iodide in 5 cc. of water. To each 
add about 2 cc. of carbon disulphide or carbon tetrachloride. 
Shake and allow to stand. Now to each test tube add a little 
chlorine water and shake. Again allow to stand (p. 162). Re- 
sult? Equations? 

7. Into four test tubes put about 2 cc. of water, alcohol, car- 
bon disulphide, potassium iodide solution, respectively. Drop a 
small crystal of iodine in each and shake (p. 162) . Tabulate the 
colours and solubilities. 

Test of iodine. 

8. (a) To a solution of starch (obtained by boiling, if neces- 
sary,) add a few drops of tincture of iodine. Result? 

(b) To a solution of potassium iodide add a little starch 
solution. Result? Now add to this solution chlorine water. 
Result? 

9. Put a small crystal of iodine in a test tube. Heat. Result? 

2. HYDROCHLORIC ACID 

(Chapter 13) 

Apparatus — Test tubes and rack. Beaker. Stirring rod. 
Burner. White Paper. 

Material — Hydrochloric acid. Sodium hydroxide. A second 
acid. A second base. Litmus. Phenolphthalein. Methyl orange. 
Sulphuric acid. Potassium chloride. 



38 



1. Action of Indicators. 



Half fill each of six test tubes with water. Number 1 to 6. 
To numbers 1, 3 and 5 add a few drops of diluted hydrochloric 
acid, and to numbers 2, 4 and 6 pour a few drops of sodium 
hydroxide solution. Into 1 and 2 pour a few drops of litmus 
solution, into 3 and 4 a little phenolphthalein, and into 5 and 6 
methyl orange. Repeat the experiment using a different acid and 
base (p. 218). Tabulate your results, as indicated below: 





Colour 

of 
Litmus 


Colour of 
Phenolph- 
thalein 


Colour of 
Methyl 
Orange 


Hydrochloric acid 








Second acid 








Sodium hydroxide 








Second base 









2. Neutralization. 

Into a beaker half full of water, add about 3 cc. of dilute sod- 
ium hydroxide solution. Add several drops of phenolphthalein. 
Stir. Place a sheet of white paper under the beaker. Now add 
slowly, while stirring, dilute hydrochloric acid till the colour just 
disappears. On the addition of a single drop of base the colour 
should begin to reappear. Explain. Equation? (See page 218.) 

3. Test for hydrogen chloride. 

Pour 1/2 cc. of concentrated sulphuric acid into a test tube 
and add a large pinch of potassium chloride. Warm gently and 
breath across the top of the tube. Result? (See page 221.) 

(The fumes observed are due to the condensation of moisture 
in the breath, as it dissolves in the gas generated.) 

4. Solubility of hydrogen chloride gas. 

Put about 1 cc. of hydrochloric acid into a test tube fitted 
with a one-hole stopper in which is a piece of glass tubing about 3 
inches long, open at both ends. Boil the acid till, on breathing 
over the end of the tubing, white fumes appear. Invert the test 
tube and quickly immerse the tubing in a beaker of water. 
Result? 



Apparat 

trough. 



3. SODIUM HYDROXIDE 

(Chapter 14) 
Test tubes and rack. Delivery" tube. Collecting 



39 

Materials — Caustic soda (sticks or pellets). Copper sul- 
phate. Ferric chloride. Lead nitrate. Ferrous sulphate. Al- 
uminum sulphate. Chalk or limestone. Ammonium chloride. 

1. Properties. 

Observe a small piece (l^ inch of stick) of caustic soda. (Do 
not handle.) Allow it to remain exposed to moist air for a few 
moments. Result? Drop the piece in about 2 cc. of water in a 
test tube. Note any change in temperature as it dissolves. Now 
dilute the solution with about 15 cc. of water. Rub a little of this 
solution between the finger and thumb. (Feel?) (See page 226.) 

2. Precipitating reagent. 

Into separate test tubes, pour about 10 cc. of each of the fol- 
lowing solutions: copper sulphate, ferric chloride, lead nitrate, 
ferrous sulphate, aluminum sulphate. To each solution add a 
few drops of the solution prepared in (1) . Results? Equations? 

Now add 2 or 3 cc. of the basic solution to each of the test 
tubes. Results ? 

3. Reaction with an anhydride. 

Prepare a test tube of pure carbondioxide. Invert it in a 
concentrated solution of caustic soda in a beaker, and allow to 
stand. Agitate a little if necessary to speed up reaction. Result? 
Equation? (See page 229.) 

4. Test for ammonium radical. 

Into a test tube place a pinch of ammonium chloride (or 
other ammonium salt) . Add about 1 cc. of caustic soda solution 
and warm. Odour? Equation? 

Repeat this experiment but use a few cc. of a solution of an 
ammonium salt instead of the solid as above. Result? 

4. NEUTRALIZATION 

(Chapter 14) 
Apparatus — 2 Burettes (50 cc). Clamp. Stand. Beaker. 
Stirring rod. 

Materials — Hydrochloric acid (1 of acid to 100 of water). 
Sodium hydroxide solution (1/10 Molar). Phenolphthalein. 

1. Titration. 

Set up two clean burettes (preferably 50 cc.) fitted with 
clamp or tap, on a stand. Fill burette A with hydrochloric acid 
(previously prepared by the teacher— 1 of acid to 100 of water) . 
Fill burette B with approximately .1 ( = 1/10) molar sodium hy- 
droxide solution (previously prepared by the teacher). Run a 
little acid and base out of each burette into a beaker. Discard 
this liquid. Now make careful readings of the amount ot acid 
and base in the burettes, by observing the position of the bottom 
of the meniscus, read at eye level. Record these readings. 



40 

Into the beaker run about 20 cc. of the acid. Add several 
drops of phenolphthalein solution. Keep a sheet of white paper 
under the beaker to aid in detecting colour changes. Place the 
beaker under burette B and run out about 10 cc. of the basic solu- 
tion, stirring constantly. Continue to add the basic solution, 
drop by drop, stirring carefully. When the addition of a single 
drop of sodium hydroxide will produce a permanent pink colour, 
which disappears by the addition of a drop of the acid, the neu- 
tralization is complete. This titration is said to have reached the 
**end point." 

Take the readings from the burettes. Calculate the volume 
of each solution used. Assuming the basic solution to be, 0.1 
normal (or 0.1 molar) , calculate the weight of hydrogen chloride 
in 1 liter of solution used. Calculate also to 2 decimal places the 
normality of the acid solution, using the formula 

Va X Na = Vb X Nb 

when V = volume 

N = normality 
A = acid 
B = base 

(Va would read "Volume of acid".) 

5. IONIZATION 

(Chapter 16) 

Apparatus — Glass plate. Test tubes and rack. 

Materials — Tartaric or oxalic acid. Slaked lime. Litmus. 
Several salts. 

1. Effect of moisture on acid and basic reactions. 

Place a clean, dry glass plate on a sheet of white paper. On 
the plate place separately a pinch of dry tartartic or oxalic acid, 
and a little slaked lime. Test the acid and lime with separate 
pieces of dry red and blue litmus. Result? 

Now moisten each of these substances with a drop or two of 
water. Again test with the litmus papers. Results? Expla- 
nation? 

2. Effect of dilution upon ionization. 

Into each of 3 dry test tubes put a small quantity (about 1 
cc.) of copper sulphate (powdered), copper chloride and copper 
bromide, respectively. In this exercise observe carefully for col- 
our changes. To each test tube add one or two drops of water, 
then slowly add more water till no further colour change occurs. 
The final colour should be a light blue. Tabulate your results in 
the following form : 



41 



Salt 


Formula 


COLOUR WHEN 


Dry 


Moist 


Concen- 
trated 
solution 


Dilute 
solution 


Copper sulphate 












Copper chloride 












Copper bromide 













Write equations indicating the ionization. 

3. Reversible reaction. 

To a solution of sodium carbonate in a test tube, add some 
potassium nitrate solution. Any reaction? Explain. Equation? 

Into a beaker put about 1 grain of bismuth trichloride. Add 
a drop or two of hydrochloric acid. If necessary add a little 
more, just enough to dissolve the salt. Now add water slowly, 
stirring constantly till a definite change occurs. Result? The 
equation for the reaction is 

BiCla +H2O BiOCl + 2HCl. 

The bismuth oxychloride is insoluble. 

Now add dilute hydrochloric acid till the reaction is com- 
pletely reversed. 

4. Cominan ion effect. 

Make a strong solution of sodium chloride in water, in a test 
tube, and then add about an equal amount of hydrochloric acid. 
What happens? Can you account for the result? 



6. HYDROLYSIS 

(Chapter 16) 
Apparatus — Test tubes and racks. 
Materials — Litmus. Several salts. 
1. Litmus reactions on solutions of salts. 

Into separate test tubes put a pinch of each of the following 
salts : sodium chloride, ferric chloride, copper sulphate, potas- 
sium nitrate, sodium carbonate, ammonium sulphate, sodium bor- 
ate (borax). To each test tube add about 5 cc of water and 
shake. Drop a small piece of red and of blue litmus into each 
solution. Examine the litmus. (See page 260.) 



42 



Tabulate your results as indicated below : 



Name of 
salt 


Formula 


Effect on 
litmus 


Acid 
Basic or 
Neutral 


Hydrogen 

ion 
concent'n 


Hydroxyl 

ion 
concent'n 


Salt 
of 


Potassium 
carbonate 


K2CO3 


Red to blue 


Basic 


Low 


High 


Weak acid 

Strong 

base 


Sodium 
Chloride 




















» 















































































2. Write an equation for each of the above reactions which 
did not show a neutral effect on litmus. (See page 261.) 

3. Write an ionic equation corresponding to each equation 
in (2). 



7. FLAME TESTS 

(Chapter 25) 
Apparatus — Platinum (or nichrome) 



wires. Burner. Co- 



balt glass. 

Material — Salts of sodium, potassium, lithium, calcium, bar- 
ium, strontium, copper. Dilute hydrochloric acid. 

For this experiment it is desirable to have a platinum wire 
for use v^ith each salt tested. In this case, the glass tube (in the 
end of which the platinum v^ire is held) should be inserted 
through a one-hole stopper. This stopper is then inserted into 
the test tube, and the test tube labelled with the name of the solu- 
tion it contains. The wire should reach into the liquid. Since 
this arrangement makes it possible to test only this one salt on 
this wire, time need not be lost in cleaning the wire after every 
test. If separate wires are not available, the platinum wire may 
be cleaned after testing a salt by alternately dipping it into a 



43 

little clean dilute hydrochloric acid, and heating, until all trace 
of the colour of the salt tested has disappeared. 

Test — Remove the wire from the solution in the test tube and 
hold it at the edge of a colourless flame. Colour ? Repeat several 
times. Observe flames of the following salts through a cobalt 
glass in addition to the regular tests : Sodium, potassium, a mix- 
ture of sodium and potassium (p. 403) . Put the corner of a cop- 
per wire gauze into a little dilute hydrochloric acid and hold in a 
colourless flame. Result? Powder a little blackboard chalk and 
apply the flame test. Colour? Clean the wire thoroughly (if 
necessary) at the end of each test. 

A salt of strontium may be tested if desired. 
Record your results in the following form : 



Element 


Formula of 
Compound 


Colour of 
Flame 


Colour 

through 

Cobalt glass 


Sample of 
Colour 































































8. ALUMINUM 

(Chapter 26) 
Apparatus — Test tubes and racks. 



Burner. Beakers (2) 



Blow pipe. 

Materials — Aluminum foil. Hydrochloric acid. Sodium 
hydroxide solution. Splint. Aluminum sulphate. Ammonium 
hydroxide. Lime water. Charcoal block. Cobalt nitrate solu- 
tion. Cotton cloth. Logwood. 

1. Action of strong acid and base 

Into each of two test tubes put about 1 sq. cm. of aluminum 
foil. To one add about 2 cc. of hydrochloric acid (concentrated) , 



44 

and to the other some caustic soda solution. Warm gently for a 
few moments. Results? Equations? 

Test any gas that is generated, with a burning splint. Re- 
sult? (See page 415.) 

2. Action of caustic soda on aluminum hydroxide. 

Half fill each of two test tubes with a solution of aluminum 
sulphate. To the first add a few drops of ammonium hydroxide 
solution, then several cc. Result? Equation? 

To the second add a little caustic soda solution, then an ex- 
cess. Result? Equations? 

3. Purification of water by aluminum hydroxide. 

Prepare some murky water by stirring a handful of soil in 
water. Allow the mixture to stand a few minutes. Then pour 
off some of the cloudy water into each of two beakers. To one 
add about 2 cc. of alum solution or solution of aluminum sulphate, 
and then several cc. of lime water. Allow to stand and observe 
at five minute intervals. The second serves as a control for pur- 
poses of comparison. Results? Equation? (See page 420.) 

4. Test for aluminum ion. 

Using a small coin, wear a depression near one end of a char- 
coal block. Fill this with some aluminum compound (moistened 
to a paste) and heat with the oxidizing flame of a blowpipe. 
Moisten the residue with a few drops of cobalt nitrate solution. 
Heat strongly again. A blue colour indicates aluminum. 

5. Aluminum hydroxide as a mordant. 

Cut two pieces of white cotton cloth. Mordant one by soak- 
ing it in a solution of aluminum sulphate and then in ammonium 
hydroxide, squeezing out the excess liquid after each soaking. 
Now place both pieces of cloth in a beaker containing logwood or 
alizarin solution. Boil for a few minutes. Wash the cloths and 
examine. Results? Equation? (See page 635.) 

9. COPPER 

(Chapter 28) 
Apparatus — Test tubes and racks. 

Material — Several salts. Nail. Potassium ferrocyanide. 
Ammonium hydroxide. Copper strip. Silver nitrate solution. 
An iron salt. 

1. Colour of cupric ion. 

Dissolve, in separate test tubes, small quantities of copper 
sulphate, copper chloride, copper bromide, sodium chloride and 
potassium nitrate. Colours? 

Write ionization equation for each of the above and state 
the colour of each ion formed. (See page 459.) 



45 



2. Tests for copper ion. 



Place a clean nail in a solution of copper sulphate. Allow to 
stand. Result? 

Add some potassium ferrocyanide solution to a dilute solu- 
tion of copper sulphate. Result? Equation? 

Add ammonium hydroxide solution, drop by drop, to a solu- 
tion of copper sulphate, till no further change occurs. Results? 
Equations? (See page 459.) 

Suspend a strip of copper in silver nitrate solution in a test 
tube. Observe frequently. Results? Equation? 

Try another strip of copper in a solution of an iron salt. Re- 
sult? (See page 396.) 

10. ZINC AND SILVER 

(Chapter 29) 

Apparatus — Charcoal block, blow pipe, beaker. 

Materials — Hydrochloric acid, zinc pellet, nail, sodium car- 
bonate, aluminum foil, badly tarnished piece of silverware, silver 
ring or dime. 

1. Galvanizing. 

Scoop a hole in the charcoal block and place zinc pellet in 
the depression. 

Take the nail and dip it into the concentrated hydrochloric 
acid. Why? Explain. (See page 220.) 

Heat the zinc pellet using the blowpipe and, while the zinc is 
molten, thrust the nail into it. What do you notice after the nail 
is removed? Explain. (See page 467.) 

2. Cleaning Silverware. 

Make a solution of sodium carbonate (10 grams of sodium 
carbonate in about 100 cc. of water) . Heat the solution to boil- 
ing point. Place the aluminum foil in the bottom of the beaker 
and the tarnished silver article in contact with the foil. Heat 
the beaker for a period of twenty minutes or longer. Remove 
the article, wash and dry. 

What do you notice? Explain, writing the necessary equa- 
tions. (See page 469.) 

11. BAKING POWDERS 

(Chapter 30) 

Apparatus — Test tubes and racks. Stand. Clamp. Deliv- 
ery tube. Burner. Beakers (250 cc). 

Materials — Baking soda. Lime water. Cream of tartar. 
Dilute hydrochloric acid. 

1. Action of heat on baking soda. 

Put about 2 grams of bicarbonate of soda in a test tube and 



46 

support this in an almost horizontal position on a stand. Ar- 
range a delivery tube so that it leads into lime water in a test 
tube. Heat the bicarbonate gently. Result? Equation? (See 
page 503.) 

2. Action of a strong acid on baking soda. 

Into a test tube put a small quantity of sodium bicarbonate. 
Have a stopper and delivery tube arranged as in part (1). Add 
a few drops of dilute hydrochloric acid to the salt and replace the 
stopper quickly. Result? Equation? (See page 366.) 

3. Reaction of a baking powder. 

Weigh out 2 gr. of potassium bitartrate (cream of tartar) . 
Calculate the weight of sodium bicarbonate needed to react with 
it (p. 365) . Weigh out this quantity and mix the two salts. Put 
half the mixture into a beaker containing 100 cc. of cold water, 
and the other half into 100 cc. of hot water. Results? Equa- 
tions? 

12. CALCIUM COMPOUNDS 

(Chapter 31) 

Apparatus — Test tubes and racks. Wire gauge. Burner. 
Evaporating dish. Broken test tubes. 

Materials — Chalk. Litmus. Plaster of Paris. Quick lime. 
Sand. Portland cement. Hydrochloric acid. Lime water. 

1. Lime. 

Place a piece of marble or chalk about the size of a pea on a 
wire and heat strongly for 20 minutes. Allow to cool. Now put 
it in a test tube and add a little water. Note any temperature 
change. Test with red and blue litmus. Result? Equation? 
(See page 511.) 

2. Plaster of Paris. 

Put a heaping tablespoonf ul of Plaster of Paris in an evap- 
orating dish. Add just enough water to make a thick paste. 
When hardened to the proper consistency, mould rapidly into any 
desired shape. Allow to harden. Equation? (See page 516.) 

3. Mortar. 

Mix together small quantities of quicklime and sand in the 
proportions of 1 to 2 by volume. Add water to make a thick 
paste. Pour into a broken (useless) test tube and allow to stand 
for a week. Break away the test tube and examine. Result? 
(See page 515.) 

4. Cement. 

Mix some Portland cement and fine sand in the proportions 
of 1 to 3 by volume. Add enough water to make a thick paste. 
Pour into a broken test tube or paper box and allow several days 
to harden. Result? (See page 551.) 



47 

5. Hard water. 

Pass carbondioxide (prepared by the action of an acid on a 
carbonate) into lime water till the precipitate at first formed 
clears. Equations? Now boil some of this clear water. Result"? 
Equation? (See page 521.) 

13. COMPOUNDS OF IRON 

(Chapter 32) 

Apparatus — Test tubes and rack. Burner. 

Materials — Ferric salts. Ferrous salts. Sodium hydroxide. 
Ammonium thiocyanate. Potassium ferrocyanide. Potassium 
ferricyanide. Nitric acid. Dilute sulphuric acid. Steel wool. 
Dilute hydrochloric acid. 

1. Tests for a ferrous salt. 

Half fill each of four test tubes with a dilute solution of a 
ferrous salt (freshly prepared). Into the test tubes put, res- 
pectively, a few drops of the following solutions: Sodium hy- 
droxide, ammonium thiocyanate, potassium ferrocyanide, and 
potassium ferricyanide. Colours? Equations? (See page 529.) 

2. Tests for a ferric salt. 

Repeat the procedure outlined in (1) but use a ferric salt 
instead of a ferrous salt in the original test tubes. Colours? 
Equations? 

Tabulate the results of (1) and (2) in the form shown be- 
low, giving the name of the salt formed, its formula and its col- 
our. Indicate any precipitates formed by an arrow (pointing 
downward). 





Ferrous salt 


Ferric salt 


Sodium hydroxide 
NaOH 






Ammonium thiocyanate 

NH4CNS 






Potassium ferrocyanide 
K4Fe(CN)6 






Potassium ferricyanide 
K3Fe(CN)6 







3. Oxidizing a ferrous salt. 

To 5 cc. of a solution of ferrous sulphate, add 1 cc. of dilute 
sulphuric acid, and then a few drops of nitric acid (concen- 
trated). Boil (CAUTION!). Test a small quantity of the re- 
sulting liquid for ferrous and ferric ions. Result? Equations? 
(See page 527.) 

4. Reducing a ferric salt. 

To 10 cc. of a solution of ferric chloride add several strands 
of steel wool (or mossy zinc). Pour in 2 or 3 cc. of dilute hy- 



48 

drochloric acid. Warm gently. Test small quantities of the so- 
lution from time to time for ferrous and ferric ions. Result? 
Equation? (See page 527.) 



14. BORAX BEAD TESTS (Optional) 

(Chapter 33) 

Apparatus — Burner. Platinum wire. Metallic compounds 
to be tested. 

Ordinary borax (hydrated sodium tetraborate) swells when 
heated owing to the evaporation of the water of crystallization, 
then melts to a colourless glassy bead, containing the oxide of 
boron, B2O3. This oxide combines when heated with several 
metallic oxides imparting characteristic colours, by which the 
metals are identified. (See page 555.) 

Bend the end of a platinum wire around the end of a pencil 
into a loop about 3 mm. in diameter. Heat the wire, and while 
still hot dip it into some powdered borax. Again heat strongly. 
Continue the process till a globular bead has been formed. 

1. Oxidizing flame. 

Pour a little cobalt nitrate on a watch crystal. Touch the 
bead while hot to a tiny particle of cobalt nitrate. Heat in the 
oxidizing (outer) flame of the burner till the bead is red hot and 
the colour uniform. Observe the colour while hot, and when cold. 
If the bead is too dark, repeat using less of the nitrate. To clean 
the bead, dip while hot into water and brush the particles away. 

Forming a new bead each time, test the following com- 
pounds: Ferrous sulphate, manganese dioxide, nickel nitrate, 
chromium sulphate. Other compounds of these metals may be 
used. 

2. Reducing flame. Repeat the experiment using the reduc- 
ing flame (tip of the inner cone) . 

Tabulate your results as shown below : 



Metal 


Com- 
pound 
used 


Formula 


Colour in 
oxidizing flame 


Colour in 
reducing flame 


Hot 


Cold 


Hot 


Cold 


Cobalt 














Iron 














Manganese 














Nickel 














Chromium 















3. Clean the bead when you have completed the tests. 



49 

15. METHANE 

(Chapter 34) 

Apparatus — Large pyrex test tube, outlet tube, stoppers, 
gas jars, pneumatic trough, mortar and pestle. 

Materials — 8 gm. anhydrous sodium-acetate, 10 gm. soda- 
lime, dilute solution of potassium permanganate. 

1. Preparation of Methane. 

Mix THOROUGHLY in a mortar, 8 gm. of anhydrous 
(fused) sodium-acetate and 10 gm. of soda-lime. Introduce the 
mixture into a large pyrex test tube and attach a glass outlet 
tube. 

Heat the test tube gently, at first, and then more strongly 
until an evolution of gas takes place. After the air in the test 
tube has been displaced, collect (over water) several jars of the 
gas. 

• Calculate how many cc, of methane (under S.T.P. See note 
page 32) should theoretically be obtainable from 8 gm. of sod- 
ium-acetate. 

Write the equation for the reaction. 

2. Properties of Methane. 

Test methane for inflammability by applying a flame to the 
mouth of one of the jars of the gas. Explain the lack of lumin- 
osity to the flame. 

Allow the gas to bubble into one of the gas jars until it is 
one-tenth full of the gas. Keep the jar inverted and permit the 
air to fill the remaining part. Apply a flame to the mouth of the 
jar containing the methane-air mixture. Why is the action rapid 
in this case? Write the equation for the reaction and calculate 
how much air (20 per cent oxygen) would be required to oxidize 
10 cc. of methane. 

Shake a few cc. of a .3 % solution of potassium permangan- 
ate in a jar of methane gas. Note whether the permanganate 
solution changes colour. If the methane gas as prepared, contains 
small amounts of easily oxidized impurities, what effects may 
they have on this test? 

16. DETERMINATION OF ACIDITY OF VINEGAR 

(Chapter 35) 

Apparatus — Burette (50 cc.) Pipette (10 cc.) Ring stan- 
dard clamp, beaker (250 cc.) . 

Materials — Vinegar or cider. Distilled water. O.IN solu- 
tion of sodium hydroxide. Phenolphthalein solution. 

(For this experiment a O.IN solution of sodium hydroxide 
should be prepared in advance as follows: Dissolve 4 grams of 
caustic soda in distilled water. Dilute to 1 liter. Stir well.) 

Using the pipette, put exactly 10 cc. of the vinegar (or cider) 
into a beaker. Add about 50 cc. of water. Add a few drops of 



50 

phenolphthalein. Fill the burette with the sodium hydroxide so- 
lution and titrate by running the basic solution into the beaker, 
drop by drop, till the end point is reached (as in exp. 4) . Record 
the volume of base used (final reading minus first reading in the 
burette). 

Repeat the titration and again record the volume of base 
used. 

Calculations : 

Concentration of sodium hydroxide solution O.IN 

Wt. of sodium hydroxide in 1 cc. of solution 0.004 g. 

Volume of basic solution used : 

first titration ■..cc. 

second titration cc. 

average cc. 

Weight of acetic acid in 10 cc. of vinegar g. 

Weight of acetic acid in 100 cc. of vinegar g. 

Normality of vinegar 

17. SOAP 

(Chapter 35) 

Apparatus — Beakers, evaporating dish, ring and stand, wire 
gauze, cheesecloth. 

Materials — 12 gm. of lard or other fat, 25 cc. denatured alco- 
hol, 3 gm. of sodium hydroxide, 3 or 4 brands of commercial soap. 

1. Manufacture of soap. 

Weigh 12 gm. of lard or other fat. Place it in a beaker and 
add 12 cc. of alcohol, and 3 gm. of sodium hydroxide dissolved in 
12 cc. of water. 

Set the beaker in a second larger beaker containing hot 
water. Stir the mixture frequently and continue heating for an 
hour. 

After this, add 100 cc. of a saturated salt solution. Cool the 
mixture and filter it through a double thickness of cheesecloth. 
Rinse the soap in the filter with 50 cc. of cold water. Press the 
soap in a small dish which will serve as a mold. 

2. Some properties of certain soap solutions. 

Dissolve small chips of commercial soaps in different beak- 
ers, using 10 cc. of water. 

To each, add a small amount of phenolphthalein. 

Result? Explain. 

Compare degrees of alkalinity. 

Should soaps be strongly alkaline? Explain. 

3. Insoluble soaps. 

Test the reaction of a soap solution with solutions of copper 
sulfate, magnesium sulfate, zinc chloride, calcium chloride. 

Results? Equations? 

What salts are present in hard water? Name some insoluble 
soaps and give their uses. 



51 

4. Emulsifying Power of Soap. 

Shake 3 or 4 drops of cotton seed oil, corn oil or olive oil 
with 10 cc. of a solution of soap. Is an emulsion produced? 
Explain how soap cleans. 

18. FOOD INGREDIENTS 

(Chapter 36) 

Apparatus — Test tubes and rack. Burner. Mortar and 
pestle. Porcelain crucible cover. 

Materials — Starch. Glucose. Cane Sugar. Fat. Oil. Egg. 
Oatmeal. Cheese. Iodine solution. Fehling's solution. Hydro- 
chloric acid. Sodium carbonate. Litmus. Benzine. Nitric acid 
(cone). Ammonium hydroxide. 

1. Test for starch. 

Put a pinch of starch in a test tube. Half fill with water. 
Shake and boil. Cool and add a drop of iodine solution (diluted 
tincture of iodine in potassium iodide solution). Colour? (See 
page 602). Test freshly cut pieces of potato and bread with 
iodine solution. 

2. Test for sugar. 

Dissolve 1 cc. of glucose in 10 cc. of water. Add 5 cc. of Feb- 
ling's solution and boil for a few minutes. The red precipitate 
formed is a test for glucose or fructose. (See page 603.) 

Repeat using a solution of cane sugar (sucrose). Result? 
Now add a few drops of dilute hydrochloric acid to a solution of 
cane sugar in a test tube. Heat to boiling. Cool. Now neutral- 
ize by adding a little powdered sodium carbonate (test with lit- 
mus). Test as above with Fehling's solution. Result? (See 
page 605.) 

3. Test for fats and oils. 

Place a drop of oil on a piece of paper. Hold to the light. 
Result? 

Put a spoonful of cornmeal or crushed peanuts in a test tube. 
Keeping away from a flame, add enough benzine or ether to cover. 
Shake. Allow to stand. Pour a few drops of the clear liquid on 
a piece of paper. Examine against the light. Result? (See 
page 606.) 

4. Test for proteins. 

Place a little of the white of a hard-boiled egg in a test tube. 
Add a few drops of nitric acid (cone). Colour? Wash off the 
acid with water. Add a few drops of ammonium hydroxide. 
Colour? (See page 608.) 

5. Test for mineral matter. 

Place half a teaspoonful of oatmeal on a porcelain crucible 
cover. Heat strongly (under a hood) , till all the carbon is burned 
away. Result? 

Samples of food such as bread, cheese, beans, lean meat, can 



52 

be tested for each of the above ingredients. If these tests are 
made, tabulate your results. 

EXAMINATION FOR THE ACID RADICLE 

The following scheme is for the identification of the anions : 
Carbonate (CO 3), sulphite (SO3 ), sulphide (S ), chloride (CI ), 
bromide (Br ), iodide (I), nitrate (NO3), phosphate (PO4), 
sulphate (S07), nitrite (NO2 ). 

Group A 

To a portion of the original solution, add dilute HNO3. No 
gas evolved. Pass on to Group B. 
If a gas is evolved : 

(1) Gas is odourless — ^test with lime water. If carbondioxide 
is present, this indicates a carbonate. 

(2) Gas has sharp odour — SO2 — a sulphite. 

Confirm by holding a drop of K2Cr04 on a glass rod in 
the gas — drop turns pale green. 

(3) Gas has odour of rotten eggs — a sulphide. 

Confirm by holding paper soaked with lead acetate solu- 
tion in gas. Paper turns brownish-black. 

Group B 

To a portion of original solution, add AgN03 solution. No 
ppte. Pass on to Group C. 
A ppte. is produced: 

(1) White ppte. — a chloride. 

Confirm by adding NH4OH in excess. Ppte. dissolves. 

(2) Cream-coloured ppte. — a bromide. 

Confirm by adding a little Mn02 and cone. H2S04to 
original solution and warming. Brown fumes of 
bromine. 

(3) Yellow ppte. — an iodide. 

Confirm with Mn02 and H2SO4 as above. 
Violet vapors of iodine. 

Group C 

Place a square of clean glass on a sheet of white paper on 
the desk. On the glass put close together a drop of the solution 
to be tested, a drop of ferrous sulphate solution and a drop of 
cone. H2SO4. With a glass rod bring these together. A brown 
colour (not to be confused with the shadow of the liquid on the 
paper) — a nitrate. Note: The brown-ring test as given on page 
288 of your text may be substituted. 

No brown colour, pass on to Group D. 

Confirm by adding a little cone. H2SO4, and some copper 
turnings to original solution. Warm. Brown fumes. 



53 

Group D 

To about 2 cc. of ammonium molybdate in a test tube, add 
about 1 cc. of original solution to which a little HNO3 has been 
added. If no immediate reaction, warm a little (do not boil) and 
allow to stand. 

No yellow ppte. Pass on to Group E. 

Fine yellow ppte. — a phosphate. 

Confirm by adding AgNOs to original (neutral) solution. 
Yellow ppte. soluble in HNO3 or in NH4OH. 

Group E 

To a portion of the original solution add BaCl2 and dilute 
HCl. 

White ppte. — a sulphate. 

Confirm by boiling. Ppte. remains. 

Group F 

If the salt is insoluble in water treat as follows : 
Put a small quantity of the salt in a test tube and add a little 
cone. H2SO4. Warm. 

(a) Gas colourless — identify as in Group A above, 

or if cloudy fumes are produced on breathing across 
mouth of test tube — a chloride. 

(b) Gas brownish — a nitrite. 

After trying several of the tests, ask your teacher for an 
unknown salt (solid) . Use part of this salt for determination of 
the cation and part for determination of the anion. Keep a com- 
plete record of the tests you make, recording all negative as well 
as positive results. 

FIRST AID 

In case of an accident or injury, notify your instructor at 
once. 

Treatment for common types of injuries in the laboratory. 
Acids — 

On the skin — Wash with plenty of water. If severe, dress 

with a paste of sodium bicarbonate. 
On the clothing — Saturate with dilute ammonium hydroxide. 
Internal — Drink lime water, milk of magnesia or baking 

soda solution. 
Bases — 

On the skin or clothing — Wash with plenty of water. Then 

apply a boric acid solution. Wash again. 
Internally — Drink juice of a lemon or orange. 

Bums — 

Apply a paste of sodium bicarbonate and water. 

Cuts — 

Clean with water. Apply tincture of iodine or hydrogen 
peroxide. Bandage. 



54 



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BIOLOGY 2 

The following exercises are designed to aid the student of 
Biology in carrying out a number of individual experiments. It 
is not expected that all those listed should be completed, but an 
effort should be made to perform as many as possible. Nor is it 
intended that they should replace those outlined in the textbook. 
Many of these, also, should be performed by the student. Stu- 
dents should be encouraged to learn much of their Biology from 
actual observations, rather than by merely reading the textbook. 

Many of the details of the experiments may be modified to 
suit the local conditions. 

Blueprints make accurate and permanent records of many 
experiments. 

The teacher should v^rite for "Turtox Leaflets," supplied free 
by the General Biological Supply House, Chicago. These give 
very helpful instructions on such items as "Mounting Insects," 
"Making an Aquarium," "The Feeding of Minute Animal Organ- 
isms," etc. The catalogue of this Supply House is most helpful to 
teachers of Biology, and may be obtained upon request. 

LIST OF APPARATUS AND MATERIALS 

Aquarium 
Beakers, 400 cc. 
Beakers, 250 cc. 
Cellophane sheets 
Cheesecloth 
Chemicals — i^ 

Alcohol 

Ammonia 

Carbondisulphide 

Chloroform 

Eosin dye 

Fehling's solution 

Iodine 

Nitric acid 
Cotton v^ool 
Cotton batting 

Cover slips (for microscope slides) 
Dissecting board 
Dissecting needles 
Dissecting pan 
Flower pots, 3" 
Flower pots, 4" 
Forceps 

Jars (of various sizes) 
Knife 

Lamp chimneys 
Magnifying glasses 
Microscope (with high power and low power) 



56 

Microscope slides 

Petri dishes 

Pins 

Sand 

Sawdust 

Soil 

Riker mounts 

Wooden flats 

Vials (wide mouth, glass) 

OUTLINE OF PRACTICAL WORK 
1. USE OF THE MICROSCOPE 

1. Learn names of the parts of the instrument; e.g., stage, 
aperture, diaphragm, mirror objective, eyepiece, etc. There 
should be screws for coarse and for fine adjustment. Mirror 
should have plane and concave sides. 

2. Preparation of object for viewing: 

The object must be transparent, a very thin section of plant 
or animal tissue, or protozoans, aphids, water fleas, moulds, 
algae, etc. 

Place the object on a clean glass slide ; place a drop of clean 
water on it (dry specimens do not transmit light efficiently), 
cover with a cover glass. 

3. Place the specimen prepared as above on the stage, and 
centre it over the aperture. 

4. Turn the mirror below the stage toward the source of 
light. If the light comes from a window, use the plane side of 
mirror; if from a lamp flame or filament, use the concave side. 

Tilt the mirror until you see the beam of light pass through 
the glass slide and specimen. 

5. See that the low-powered objective is in place above the 
specimen. With your eye on the level of the stage, turn the ob- 
jective down until it almost touches the cover-glass. (Never turn 
screws to lower objective, with your eye to the eyepiece, unless 
the specimen is plainly in view.) 

6. Now place your eye above the eyepiece. Light should be 
coming through to your eye. Turn the screws to raise the ob- 
jective. Continue until image of specimen comes into view. 

7. Now that you have the specimen in view, several im- 
provements may be made. Experiment with mirror and with 
diaphragm until you have the best possible light arrangement. 
With eye still placed to the eyepiece, take the slide on which 
specimen is placed in both hands and move it gently back and 
forth to view different parts of specimen. 

8. If you desire a higher magnification, there are several 
methods you may adopt. You may replace the eyepiece with one 
of higher power. You may raise the eyepiece by lengthening the 



57 

tube between objective and eyepiece and then re-adjusting the 
focus. Or you may replace the objective with one of higher 
power. For the high power objective you will need more light. 

2. THE AQUARIUM 

Every biology classroom should have an aquarium. Com- 
plete instructions on making one will be found in ''Everyday 
Biology," pages 636-8. Water weeds may be anchored to the bot- 
tom by tying a glass stopper or a piece of glass tubing to the 
lower end of the plant. Roots should soon strike into the sand. 
In addition to fish, snails should be present. If the aquarium is a 
large one, salamanders may also be stocked. However, these 
have a tendency to attack the fish, and so are better kept by them- 
selves. If it is desired to hatch frog tadpoles from eggs, or young 
snails from eggs, the fish must be removed. If the water be- 
comes m.urky, it probably indicates the presence of too many 
animals. 

THE TERRARIUM 

''Everyday Biology" also gives directions for the making of 
a terrarium (page 645). A desert terrarium, including a few 
cacti and "horned toads," makes a very interesting display. 
"Horned toads" (lizards) may be obtained from the Biological 
Supply House, Chicago. 

3. MICROSCOPIC ORGANISMS 

(For all students) 

Materials: Small quantity of organic matter: a handful of 
grass, dry hay, dead leaves, slices of carrot, etc. 

Procedure: Place any of the above in a jar of water and 
leave in a warm place, 70-90 degrees Fahrenheit, for several 
days. 

Take a clean glass slide. Place upon it a drop of clean water. 
Pluck a few threads from an old piece of clean cotton and pick 
them apart with a needle until the fibres are very finely divided. 
Place these in the drop of water on the slide. These fibres form 
a trap which restricts the movements of the protozoa and allows 
the observer to keep them in view. 

Now take a sample of the infusion from the jar and place a 
drop of it among the wet fibres. Cover with thin glass. Exam- 
ine with the low power objective of the compound microscope. 
There are certain to be paramecia and other ciliata, and you 
may be fortunate enough, if your infusion was made with decay- 
ing leaves, to find amoebae. The latter are more likely to be 
found at the bottom of the jar. 

Water from Sloughs and Ponds — 

Samples should be collected from as many of these sources 
as possible. If there is a green scum on the water there are sure 
to be algae, such as closterium, ulothrix, spirogyra. 



58 

On the edges of leaves under water, the protozoan, vorticella, 
is usally found. Place the wet leaf on a slide and bring the edge 
of leaf into sharp focus with the low power of microscope. Then 
move the slide carefully, keeping the edge always in view. 

Vorticella may be recognized by its bell-shaped body, the 
ring of waving cilia around the mouth, and by the long coiling 
thread which attaches it to the leaf. Larger organisms, rotifers, 
Cyclops, daphne, etc., visible to the naked eye, may also be found 
in pond water. These make suitable specimens for microscopic 
studies. 

Soft jelly-like masses may often be found on decaying wood 
in pond water. These are fresh sponges. Some ponds contain 
hydra, usually found on the stems of bullrushes under the sur- 
face of the water. 

4. BACTERIA 

(For several students) 

Bacteria are minute fungus plants that are either parasites 
or saprophytes. They are widely distributed and can be grown 
on artificially prepared media. 

Materials: Beaker 400 cc. ; test tubes; funnel; flask; cotton 
wool; Petri dishes; burner; water; agar-agar; beef extract; a 
piece of cotton. 

Procedure: Into the beaker containing about 200 cc, of dis- 
tilled water, put 3 grams of agar-agar and about 1 gram of beef 
extract. Dissolve the agar-agar by heating the water. Strain 
through cotton into a flask and heat again. 

Sterilize the Petri dishes and test tubes by boiling in water 
for 5 minutes. Pour the sterile medium into the Petri dishes or 
half fill the test tubes. Cover the dishes and plug the test tubes 
with cotton wool. Rest the test tubes at an angle to form a larger 
surface. Allow the liquid to stand till cool and firm. 

Set one test tube aside as a control. 

Remove the cotton wool from a test tube or the cover from a 
dish and expose contents to the room air for ten minutes. Cover 
as before and label. Similarly expose other culture media to (1) 
a drop of dirty water, (2) a drop of milk, (3) dust from the 
desk, (4) your finger. Cover and label. The dishes containing 
the drops of liquid should be shaken to spread the liquid. Set the 
dishes in a warm dark place. 

Examine after several days. Note the number of colonies, 
colour, shape, rate of growth. Record your observations. When 
a culture is sufficiently developed make an accurate record in the 
form of a drawing. 

5. MOULDS 

(For several students) 
Materials : Saucer ; large beaker ; piece of bread. 

Procedure: Moisten a piece of bread. Either leave it exposed 
for several hours, or sprinkle with dust from two or three 



59 

sources. The bread may be dusted with other mould spores, if 
available. Cover the bread with the beaker, and set aside in a 
warm place. Examine daily. When growth begins, examine 
closely with a magnifying glass, and under the microscope. 

Record your observations with diagrams. 

Several kinds of moulds may be found. 

If you have been successful in obtaining the "black mould," 
place a black sporangium (see page 125 in textbook) on a glass 
slide. On it place a cover slide and press gently so as to crush the 
sporangium. Now examine under the microscope, first low, then 
high power. 

Additional Experiment on Moulds 

(For all students) 
Materials: Test tubes; cotton wool; clear fruit juice. 

Procedure: Put a few cc. of fruit juice into 2 or 3 test tubes. 
Add an equal volume of water. Shake. Inoculate the liquid by 
adding a little mould to it, or by sprinkling it with dust. Plug 
the test tubes with cotton wool, and set in a warm place. 

Observe as above and record your observations. 



6. DISSECTION OF EARTHWORM 

(For pairs of students) 

Materials: Dissecting pan; forceps; scissors; dissecting 
needles ; pins. Dissect under water, renewing water frequently. 

1. Lay the specimen on board, dorsal side uppermost; stretch 
and pin at ends, slanting pins away from the worm. Make an 
incision through the skin near the posterior end and to one side 
of the dorsal blood vessel. With scissors cut forward along a line 
parallel to the intestine until the anterior end is reached. With 
forceps, lift the cut edge of the body wall and run a dissecting 
needle along the side of the intestine to cut the partitions that ex- 
tend from intestine to body wall. Turn the edges of the body 
wall back and pin them down, slanting the pins so that they are 
out of the way. 

2. The intestine is the most prominent organ disclosed. ^ It 
is dark-coloured from its contents and nearly fills the body cavity. 

3. Along the top of the intestine is the dorsal blood vessel. 

4. With a lens, observe the partitions. How do they corres- 
pond to the segments you have observed in the external surface? 

5. In the first six segments (anterior end) you will find more 
muscle tissue than in the remainder of the body. These are at- 
tached to the pharynx. 

6. On the dorsal side of the second segment you should see 
two ganglia, white masses of nerve tissue which serve as a brain. 



60 

From these, a nerve cord passes on either side of the pharynx to 
rejoin in a thin white thread which extends the entire length of 
the ventral side. You may be able to see it with a lens. 

7. In the region of the tenth segment are the sperm sacs, 
several pairs of white bodies, plainly visible. 

8. Lying in segments eight to twelve are the aortic arches. 
These serve as hearts to pump the blood. They can be traced 
from the dorsal blood vessel to the ventral blood vessel. ' The 
aortic arches may be seen best by anesthetizing a living worm 
(chloroform or ether) , and holding it up by the extreme posterior 
end, swinging it around several times until the centrifugal force 
causes the blood to collect in the anterior end. If it is then 
opened, the aortic arches will be found distended with blood. 

9. When the sperm sacs are removed, you may find in the 
ninth and tenth segments two small pairs of white spherical bod- 
ies, the sperm receptacles or spermathecae. 

10. The ovaries may be found in the thirteenth segment. 

11. Trace the alimentary canal. The mouth occupies seg- 
ments one and two ; the pharynx, four to five ; the oesophagus, six 
to fourteen ; the crop, fifteen to sixteen ; the gizzard, seventeen to 
eighteen. The intestine occupies the remaining segments. 

12. Remove the intestine, noting the ventral blood vessel and 
nerve cord. 

13. Attached to the ventral side of each segment is a pair of 
tubes thrown into many loops. These are the nephridia or 
kidneys. 

14. Examine the body wall under a lens and later with mic- 
roscope. The outer layer peels off easily and is very thin. This 
is the cuticle. The next layer is composed of circular muscles, 
and the third, of longitudinal muscles. 

15. Mount a drop of liquid found in the body cavity under the 
microscope. The white corpuscles are clearly seen. 



7. THE GRASSHOPPER 

(For all students) 

Materials: Grasshopper; dissecting needle, or large pin; for- 
ceps; magnifier; white paper. 

Procedure: Examine the general structure of the insect, us- 
ing the magnifier as an aid. Note the three distinct body di- 
visions. Name these. Draw the grasshopper (side view) and 
label the main features. 

Head — Examine the head with the glass. Locate the follow- 
ing parts — feelers, compound eyes, simple eyes (ocelli), mouth, 
palps. With the aid of the forceps, carefully remove the mouth 
parts and arrange them on a sheet of paper in their relative posi- 



61 

tions — upper lip, lower lip, mandibles (hard, black jaws), maxil- 
lae (bearing palps), tongue. 

Make a diagram of the mouth parts as arranged. Label each 
part. (Diagrams of mouth parts may frequently be found in 
reference texts.) 

Thorax — Note the shape of the thorax and its three seg- 
ments (prothorax, mesothorax, metathorax). Note the number 
of wings, their structure and shape. To what segments of the 
thorax are they attached ? Compare the under wing and the top 
wing. 

Examine the legs and note their insertion on the thorax. 
Hunt up in a reference text the names of the different segments 
of the leg. 

Abdomen — Count the number of segments. Locate the spir- 
acles and count them. The ear of the grasshopper can be easily 
seen on the front segment of the abdomen above the insertion of 
the large jumping leg. The end of the abdomen of the female is 
modified into an ovipositor or egg layer. 

Using a sharp knife or razor blade, slice a thin section of the 
compound eye and examine under the microscope. 

A cabbage butterfly may be examined if desired. A piece of 
a wing should be examined under the microscope to observe the 
scaly covering. This will be more easily observed if some of the 
scales have first been removed by rubbing the wing with the 
finger. 

8. INSECT LIFE HISTORIES 

(Class project) 

Materials: Flower pots; lamp chimneys; cheesecloth; rub- 
ber bands ; soil ; plants or twigs for insect food. 

Procedure: Collect insect eggs or larvae. Note the kind of 
plant upon which each is found in order to supply the proper 
food. Fill the pot with soil. Close the top end of the chimney 
with cheesecloth held with the rubber band. Place a young plant 
or twig in the soil. Add water. Put the eggs or larvae on the 
plant and set the chimney over the plant. 

Make daily records of any changes which occur. 

The develpoment of mosquitos from eggs can be readily 
watched by placing the eggs in a beaker of rain water (or slough 
water), setting the beaker on the soil and covering with the 
chimney. 

Permanent Life History Exhibits 

Suggested exhibits to be made by different groups of stu- 
dents are: Grasshopper, monarch butterfly, honey bee, potato 
beetle, cutworm, dragonfly, housefly, promethia moth, red under- 
wing moth (catocala) . 



62 

Cocoons containing living pupae of the large silk moths may 
be obtained from the General Biological Supply House, Chicago. 
When hatched, excellent exhibits of these may be made, showing 
the cocoon (outside and inside), pupal case (in cocoon) and 
adults (male and female). 

Materials: Riker mounts (or cigar boxes, cotton batting and 
cellophane) ; small wide-mouthed vials; alcohol; specimens. 

Procedure: Place a few eggs of the cabbage butterfly (the 
common white) , obtained from the leaves of the cabbage in early 
summer, in a vial. Add alcohol and stopper tightly. Later place 
one good sized larva in a second bottle. Add alcohol and stopper. 
Repeat later with a pupa in a third bottle. Mount a specimen of 
the adult butterfly with wings spread. Do not use a pin in the 
thorax. The body may be held firmly in position in the groove of 
the mounting board by placing pins against the body behind the 
wings. 

Spread a layer of cotton batting in the cigar box, sufficient to 
fill the box. Place the bottles and the adult insect in position on 
the batting. Identify each by a typewritten label. At the bot- 
tom of the exhibit place another label on which are shown the 
names (scientific and common), date collected, etc. Paste the 
sheet of cellophane over the box. The sheet should press lightly 
on the specimens. Riker mounts are more satisfactory than 
cigar boxes, but also more expensive. 

9. CLASSIFICATION OF INSECTS 

(For all students) 

Materials: Several specimens of insects, including some of 
the following : Housefly, grasshopper, moth or butterfly, bee, dra- 
gonfly, potato beetle, stink bug, mosquito. 

Using the following key, classify each specimen : 

Key 

Order 

With two wings only Diptera 

With four wings — 

Outer pair of wings hard and shell-like... Coleoptera 

Outer wings with the front half hard and the 

rear half membranous Hemiptera 

Wings much alike^ — 

Both pairs of wings colored; covered with 

scales Lepidoptera . 

Wings thin and transparent — 

Outer wings folded over inner fan- 
like wings; held close along body 

when at rest Orthoptera 

Wings held at right angles to the 
body — 
Mouth parts for sucking and 

Chewing Hymenoptera 

Mouth parts for chewing.., Odonata 



63 

In your note book (1) copy the "key'', (2) write down the 
Orders listed in the key with the name of insects classified in 
each Order. 



10. DISSECTION OF FROG 

(For small groups of students) 

Materials: Frog; dissecting board; pan; dissecting needle; 
scissors; knife; forceps; pins; probing rod. 

Procedure: 

1. If the frog is living, place it in a wide-mouthed jar. Pour 
ether or chloroform on a piece of absorbent cotton and drop the 
cotton in the jar. Seal and leave for half an hour. 

2. Place the frog on its back on a dissecting board. Stretch 
the forelegs well forward and tack them to the board. Stretch 
the hind legs well back and tack them. With forceps pinch up a 
fold of skin near the pelvis. With scissors, snip through the skin 
and slit the skin from pelvis to chin. Loosen the skin wherever 
it adheres to the underlying tissues and turn it back. 

Cut outward from the centre line to each leg and slit part 
way along the leg. Pin the skin back so that it is out of the way. 

Cut through the muscular wall of the abdomen and carry the 
cut forward in the same way as with the skin. Be careful to keep 
this cut a little to one side of the centre line and watch the point 
of the scissors to see that no internal organs are injured. Tack 
the flaps of the abdominal wall. 

3. The most prominent organs in the body cavity are the 
liver, and, if the frog is a female, the oviducts. It may be neces- 
sary to lift or remove these to see the other organs. The liver is 
chocolate-coloured and has several lobes. If the oviducts are 
filled with eggs they will appear black, owing to the colour of the 
eggs; if not, then they appear as long white tubes. They must 
not be confused with the intestine. 

4. At the anterior edge of the liver and between the lobes is 
the reddish heart. It is enclosed in a very thin transparent sac, 
the pericardium. Pinch this vip with the forceps, cut through it 
and remove most of it. If the frog is freshly-killed, the heart 
may be still beating. The main artery from the ventricle divides 
into two branches, right and left, and each of these into three sub- 
divisions : 1, to the head, the carotid ; 2, to the body, the aorta; 3, 
to the lungs and skin, the pulmo-cutaneous. 

You may puncture the heart and probe with a blunt wire to 
trace the arteries and veins. Later, if you wish, you may dissect 
the heart. 

5. On either side of the heart and partly hidden by the liver 
are the two lungs. If they are collapsed, they may be inflated 
with a glass tube or blowpipe applied to the glottis. Compare 
them with lungs of a bird or mammal. 



64 

6. Push the liver aside to expose the stomach. Probe from 
the mouth through oesophagus to stomach with a blunt rod. 

7. At the posterior end of the stomach is the intestine. 
Trace it throughout its course. How does it compare in number 
of folds with: a fish? a duck? a chicken? or a rabbit? 

8. Notice the thin membrane which stretches from fold to 
fold of the intestine. This is the mesentery. Where is it at- 
tached to the body wall ? Notice the blood vessels which form a 
network in the membrane. Where are the capillaries which con- 
nect arteries and veins? 

9. The pancreas lies in the first fold of the intestine and the 
stomach. It has the appearance of a yellow cord with lateral 
branches. 

10. The intestine empties into an organ called the cloaca. 
This receptacle receives the wastes from the intestine, the urin- 
ary bladder, and also the sperms or eggs from the reproductive 
organs. 

11. On the dorsal side of the body cavity and on either side of 
the cloaca is a flattened, reddish body, the kidney. 

12. Near the ventral surface of each kidney is the spermary 
or ovary, depending upon the sex of the frog. Sperm ducts or 
oviducts lead from these to the cloaca. 

13. The spleen is a small red spherical body close to the left 
kidney. 

14. The thyroid glands may be found on either side of the 
oesophagus near the pharynx. 

11. CORPUSCLES OF FROG OR FISH 

A live frog is enclosed in a small cloth bag with a draw- 
string tightened around the hind leg so that only the foot 
protrudes. 

The bag may be secured with strings to the stage of the mic- 
roscope so that the webbing of the extended foot is over the aper- 
ture and under the low power objective. 

The webbing of the foot is suflficiently transparent to enable 
the student to watch the corpuscles flowing through the veins and 
capillaries. 

An even better view of corpuscles, coursing through blood 
tissues, may be seen in the tail of a goldfish or minnow. Wrap 
the live fish in a clean wet cloth with only the tail protruding. 
Place the tail on a wet glass slide and view under the low power 
of the microscope. 

Tadpoles may also be used for this purpose, if they are 
caught in the stage when they are breathing by external gills. 
The circulatory system where it passes through the gills may 
easily be seen. The tiny tadpole can be placed on the glass slide 
with its gills in contact with the glass. 



65 

12. GERMINATION OF FERN SPORES 

(For two or three students) 

Materials: Culture dish or saucer; small unglazed plant pot, 
3"; large beaker; moss (sphagnum moss, if available) ; fern 
spores; water. 

Procedure: Fill the pot with the moss or some suitable sub- 
stitute. Wet moss and pot thoroughly. Invert the pot with moss 
and place on the bottom of a Petri dish or in the saucer. Dust 
the fern spores (from sporangia) liberally over the damp pot. 
Add a little water to the dish and cover with a large beaker. Set 
aside at room temperature. These spores may take weeks to 
germinate. 

Examine from time to time and when germination begins, 
as seen by the green colour, remove a few prothallia to a glass 
slide. Add a drop of water and cover with a cover slip. Exam- 
ine under the low power of a microscope. 

Make a cross section diagram of the apparatus and label. 
Draw several successive stages in the germination as seen under 
the microscope. 

13. STRUCTURE OF MONOCOTYLEDONS AND 
DICOTYLEDONS 

(For all students) 

Materials: Young stems of plants; geranium, fuchsia, lilac, 
maple, etc. ; ink or dye ; razor blade ; magnifier ; microscope. 

Procedure: (1) Stems: Dicotyledons. Make thin slices of 
stem of geranium, fuchsia, etc., and examine them under the low 
power of the microscope. Cut stems of the same plants and of 
lilac, willow, maple, etc., with vigorous leaf systems. Place the 
cut ends in a jar of dye (eosin, weak solution of red ink, etc.). 
Leave for one or two days. Remove and slice thin cross sections. 

Notice the tissues that have carried the dye. How are they 
arranged? (The wood cells, xylem, carry liquids upward in the 
stem.) 

Examine the slices with a hand lens and with a microscope. 
Notice the epidermis, the cortex, bast, wood, and pith. The wood 
should show the stains from the dye. The bast should be un- 
coloured, but should be in the same bundle with the wood and 
toward the outer edge of the stem. Cells of pith and cortex are 
much larger than wood and bast cells, the pith in centre of stem, 
and extending outward between bundles of wood. The cortex 
lies outside of the bast and extends inward between the bundles. 
The cambium layer is not a part to be seen as a distinctive type 
of cell. It is the region of growth, and new cells of wood, bast, 
pith and cortex are being formed there during the growing sea- 
son. When cells are growing most rapidly the walls will be 
weak, and a sharp twist will sometimes separate bast and cortex 
from wood and pith. (Every boy has done this in making willow 
whistles.) This is a good method for locating the cambium layer. 



66 

Stems: Monocotyledons. Repeat the above procedure with 
steins of corn, onions, lilies, cereals, dates. Dye rises in the wood, 
as before, but the coloured tissues will be found in a different pat- 
tern. Bast and wood are still bound in bundles, but these bundles 
are scattered in the pith. 

(2) Leaves. Collect and compare leaves of monocotyledons 
and dicotyledons. Generally speaking the former are parallel- 
veined, and the latter, net-veined. 

(3) Flowers. Collect and compare flowers of the two classes. 
Count the petals, sepals, stamens, lobes of stigma, sections of 
ovary, etc. Monocotyledons generally have these parts in mul- 
tiples of three, dicotyledons, in multiples of four or five. 

(4) Seeds. Collect and soak seeds of flowering plants. Re- 
move the testa or outer covering ; the origin of the terms ''mono- 
cotyledon'' and "dicotyledon" should be clear. In dicotyledons, 
e.g., beans, peanuts, etc., the seeds should divide easily into two 
parts, the cotyledons. 



14. FOOD CONTENTS OF SEEDS 

(For all students) 

Seeds contain one or more of the following food materials — 
starch, protein, fat, oil, mineral matter. 

Instructions for making tests for determining the presence 
of any of the above materials may be found in Exercise No. 15 
of the Chemistry experiments. 

15. IDENTIFICATION OF TREES 

(For all students) 

During their study of Biology, students should become fa- 
miliar with the names and appearance of several of the common 
trees and shrubs of the district. The following exercise should 
be carried out in the early spring, when the buds are beginning 
to expand. 

Materials: Young, vigorous twigs (length 5") of several trees 
and shrubs : poplar, birch, maple, Manitoba maple, ash, elm, lilac, 
willow, tamarac, pine ; magnifier ; dissecting needle. 

Procedure: Note carefully the following features: 

(1) Colour and appearance of bark of stem. 

(2) Relative position of buds on stem (opposite one an- 
other or alternate). 

(3) Shape and colour of buds. 

Remove one large bud and carefully dissect it, placing the 
scales and leaves on a sheet of paper in order as they are re- 
moved from the bud. Note the young stem which remains after 
all leaves are removed. 



67 

Make a drawing to show these scales and miniature leaves. 

In your notebook, rule a page aS shown below, leaving plenty 
of space for the drawings. Under the headings "Twig'*, "Bud" 
and ''Leaf", make careful drawings of these parts. Rule a space 
for each plant examined. 



Plant 


Twig 


Bud 


Leaf 


Lilac 

















16. SEED STRUCTURE 

(For all students) 

Materials: Bean seeds and corn seeds soaked for 24 hours; 
magnifier; iodine (weak solution). 

Procedure: Bean : On the testa or seed coat, find the hilum or 
scar where the seed was attached to the pod. Near the hilum is 
a tiny opening, the micropyle^ which admitted the pollen tube to 
the ovule. Make two drawings of the bean, one side view, the 
other from above, showing the hilum. Label. 

Remove the testa. Note the two cotyledons, held together by 
the embryo. Open the two parts, carefully breaking them apart. 
Locate the ^niule or little leaves, and the stem or hypocotyl. 
Make a drawing and label. 

Corn : Make two drawings of the corn seed — ^f ront and side 
views. Note the light coloured area — the embryo. Cut the seed 
lengthwise through the embryo. Stain the cut surface lightly 
with the iodine and note which part contains the starch. Ob- 
serve the embryo — plumule, hyprocotyl and cotyledon. Make a 
diagram and label. 



17. SEED GERMINATION 

(For several groups of two or three students) 

Materials: Flat wooden boxes; sawdust, sand or soil; bean 
seeds ; pea seeds ; corn seeds. 

Procedure: Soak all seeds for 24 hours before planting. In 
the box, plant 20 to 30 seeds of each kind. Keep the sand moist, 



68 

but not too w€t. Dig up a few seeds every other day and record, 
by labelled drawings, the successive stages in the growth of the 
seedlings. 

This experiment may be varied to suit the size of the class. 
If desired, a number of seeds may be planted at intervals of three 
days, thus giving, in time, a complete series of stages of growth. 
One class period would then enable the students to record the 
complete series. 

By keeping some boxes in bright light, while others are kept 
in a weaker light, the effect of light upon the growth of the seed- 
lings may be studied. 

In small classes, students (in pairs) may be required to 
carry out the entire experiment. 

Among the factors to be noted are : 

(1) Time required for germination. 

(2) First part of embryo to break through the testa. 

(3) Part to appear first above ground. 

(4) Position of cotyledons in seedlings. 

(5) Rate of growth. 

MUTILATION OF SEEDLINGS AS METHOD OF STUDYING 
FUNCTIONS OF DIFFERENT PARTS 

(For several students) 

In trays, plant rows of seeds. Sawdust is easier to use than 
soil. When germination has taken place and the leaves are be- 
ginning to appear above the surface of the sawdust, dig up speci- 
mens carefully; from one cut off the cotyledons or remove the 
endosperm ; from another remove the radical ; from another the 
plumule. Replant all parts, labelling them with distinctive num- 
bers or words. Continue to water all specimens. Keep a record 
of their subsequent progress. Be sure to leave two or three 
plants uninjured as a control. 



18. FLORAL STRUCTURE 

(For all students) 

Materials: A few complete flowers, such as lily, radish, pe- 
tunia, buttercup, sweet pea; needle; magnifier; forceps; white 
paper; knife. 

Procedure: Examine the whole flower, noting the different 
parts from outside and inside. Cut the flower through the middle 
and make a drawing of the parts observed. The base of the 
flower is known as the receptacle. On this are the sepals com- 
posing the calyx. Note their shape, colour, size, number and 



69 

whether they are united or separate. The next envelope is the 
corolla, composed of petals. Examine these as you did the sepals. 
The stamens consist of filaments and anthers. Examine the an- 
thers carefully, cutting them open to observe the pollen grains. 
Examine some pollen under the microscope. In the centre of the 
flower is the pistil. It consists of ovary, style, and stigma. Feel 
the stigma. 

Complete the following table in your notebook. Make draw- 
ings under the heading ''shape.'' 



Part 


Colour 


Shape 


Composed 
of 


Function 


Receptacle 










Calyx 










Corolla 










Stamen 










Pistil 











19. GERMINATION OF POLLEN GRAINS 

(For several students) 

Materials: Petri dishes or saucers; sugar; water; pollen 
grains of several kinds of flowers. 



70 

Procedure: In 100 cc. of water dissolve about 1 gram of 
sugar. Boil for a few minutes. When cooled pour a little solu- 
tion into each of the dishes. Dust some pollen grains from the 
anthers of a flower onto the solution. Cover and set in a warm 
place till next day. Examine some drops of water under the mic- 
roscope — first low power, then high power. 

Make drawings of your observations. 



20. SNAILS' EGGS 

An interesting study may be made of cleavage of fertilized 
cells and embryonic development if a few mature snails are kept 
in a glass jar in the classroom. 

Egg clusters are deposited on the sides of the jar. These 
may be scraped off with a sharp knife and examined under the 
microscope. Sperms may sometimes be detected under the high 
power objective, swimming in the water surrounding the eggs. 

If taken soon after fertilization takes place, the egg may be 
seen going through the process of cleavage. The one cell may 
be seen dividing into two, the two into four, and so through other 
successive stages, blastula, gastrula until shells are formed and 
the young snails are ready to emerge from their gelatinous 
envelope to forage for themselves and live their independent 
lives. 



21. WEEDS OF ALBERTA 

(For all students) 

Materials: Complete specimens of several weeds common to 
your locality. Magnifying glass. 

An herbarium of weeds should be prepared for every biology 
laboratory. These specimens should show as many parts of the 
plant as possible, and after being pressed and dried between 
large sheets of blotting paper, they should be neatly mounted 
on regular mounting sheets, and accurately labelled. Thick roots 
should have the back sections cut away. Freshly collected weeds 
are, however, preferable for study. 

Coloured charts of Alberta weeds may be obtained from the 
Department of Agriculture, Edmonton. 

Using a full page in your notebook, rule a table, as shown 
below. Under the headings— "Leaf ," "Flower,'' "Seed or Fruit," 
make drawings of these parts respectively. Ten or twelve of the 
noxious weeds in your neighborhood should be examined. 



71 



Weed 


Habitat 


Leaf 


Flower 


Seed or 
fruit 


Character- 
istics 



















































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